# 99% of People Can't Name All These Shapes. Can You?

By: Craig Image: n/a

One of the first things you learn as a toddler is that you can't fit a square peg in a round hole, no matter how hard you try. But as you grow up, you learn about more bewildering and complex shapes that exist in two or three dimensions and often have a bizarre set of physical properties, from a center of gravity in an unexpected location, to the ability to spin in one direction and not the other, to being technically innocent but thoroughly reminiscent of something very naughty indeed.

Some shapes derive their names from Greek or Latin origins, while others are named for the popular toy, tool or symbol that makes use of them. Some appear in everyday life, whether by design (literally) or simply baked into nature's lines in the form of sunflowers and golden ratios. Others are rarer, meaning you might not recall their names - mainly because you don't necessarily need to remember the name of a twelve-sided shape in order to get through your ordinary day. Either way, there was probably a time that you knew all of their correct names, even if just to get yourself through the SAT. So click on through and let's see how much you've retained! Which shape is shown here?
Circle
A circle is a two-dimensional shape where the boundary of the circle is always the same distance from its center point. It basically is a line that meets itself. A circle consists of a number of properties, including a circumference, a radius, a diameter, and an area.
Oval
Ellipse
Square Which shape is shown here?
Pentagram
Cube
A cube is a three-dimensional box shape which is symmetrical and consists of six equal box shapes, all with the same length sides and the same internal and external angles.
Hexagram
Crescent Which shape is shown here?
Henagon
Equilateral Triangle
This type of triangle has three equal length sides and three equal angles that add up to 180 degrees. Each of the three angles must, therefore, be 60 degrees.
Digon
Kite Which shape is shown here?
Rhomboid
Hendecagon
Hexagonal Pyramid
This three-dimensional figure has a hexagon base and then six equal triangles protruding upwards from that base. It also has seven vertices and twelve edges. Which shape is shown here?
Lozenge
Trapezoid
Irregular Triangle
An irregular triangle, also called a scalene triangle, has three unequal sides and three unequal angles. Which shape is shown here?
Circle
Square
Octagon
Pentagon
A pentagon is a two-dimension figure with five equal straight sides and five equal internal angles. The angles, when added up, will equal 540 degrees. Which shape is shown here?
Deltoid
Decagon
Decagons consist of 10 sides. They can be regular, where all sides are of equal length and all angles the same, or irregular, where sides are different lengths and angles inside the decagon vary. Note that whether the decagon is regular or irregular, the angles inside will add up to 1440 degrees.
Triquetra
Salinon Which shape is shown here?
Right Triangle
Also known as a right-angled triangle, this triangle will always have two sides forming a 90 degree angle. The other two can be anything else, but together will always make the other 90 degrees.
Digon
Henagon
Kepler Triangle Which shape is shown here?
Rectangle
Pentagon
Irregular Octagon
Both regular and irregular octagons have eight sides. Unlike a regular octagon where the sides are all equal length, an irregular octagon features irregular sides and angles. The angles, however, will always add up to 1080 degrees.
Rhombus Which shape is shown here?
Hexagon
A hexagon is a six-sided figure with equal sides. The angles inside are each 120 degrees, adding up to a total of 720 degrees. Of course, thats a perfect hexagon. Sides can be of different lengths and angles can change, but they will always add up to 720 degrees.
Isosceles Triangle
Trapezium Which shape is shown here?
Square
Parallelogram
Rectangle
This two-dimensional shape has opposite sides of equal length. All four internal angle are 90 degrees, adding up to 360 degree in total. To find the area of a rectangle, all you need to do is multiply its width by its height.
Circle Which shape is shown here?
Rational Triangle
Oval
Square
Crescent
A two-dimensional shape that is thinner at the ends where it curves than its middle section. It is often used to describe the moon, but is also found in religion, particularly Islam. Which shape is shown here?
Octagram
Lune
Ellipse
An ellipse is like a circle but differs in the fact that it looks like it has been slightly squished. A circle is considered to be an ellipse.
Disc Which shape is shown here?
Square
Octagon
Convex Pentagon
Simply put, a convex polygon has all its interior angles less than 180 degrees. As soon as one of the angles goes above this number, it becomes a concave polygon. Note that all the vertices of the polygon point away from the center of this two-dimensional object.
Dodecahedron Which shape is shown here?
Square
This two-dimensional figure consists of four equal sides with four internal angle of 90 degrees. These angles add up to 360 degrees. All opposite sides are also parallel.
Rectangle
Triangle
Circle Which shape is shown here?
Lens
Arch
Isosceles Triangle
An isosceles triangle has two sides of equal length with two equal, internal angles corresponding to those sides. The sides and the angles are sometimes called congruent, which basically is a fancy word for equal.
Scalene Triangle Which shape is shown here?
Disc
Rectangle
Parallelogram
A parallelogram is a four-sided figure where the two opposite side are parallel. For instance, a square, a rhombus and a rectangle, although all different, are parallelograms.
Rectagon Which shape is shown here?
Decagon
Nonagon
Cone
This three-dimensional shape consists of a circular base. It has a curved surface that reaches up to form a tip. This is known as the apex of the cone.
Right-angle Triangle Which shape is shown here?
All quadrilaterals are polygons. When they are irregular, their sides are not the same, unlike a regular polygon where all sides and angles are congruent. The angles, however, will still add up to 360 degrees.
Acute Triangle
Decagon
Heptagram Which shape is shown here?
Triangle
Rectangle
Heptagon
A heptagon is a figure that has seven equal sides and equal angles. It is a polygon and can sometimes be called a septagon. Which shape is shown here?
Rectangle
Trapazoid
Obtuse Triangle
An obtuse triangle features an angle with more than 90 degrees. Only one side can be obtuse, otherwise the points of the triangle will never meet. If one angle is obtuse, the other two angles can only add up to 90 degrees.
Bankoff Circle Which shape is shown here?
Lozenge
icosagon
Triangular Prism
A triangular prism is a three-dimensional object. It consists of three sides that are shaped as rectangles and two bases in the shape of triangles. Which shape is shown here?
Convex Octagon
Octagons can either be convex or concave. A convex octagon will have all its eight angles pointing in an outwards fashion. None of these angles can be more than 180 degrees in size.
Hexagon
Decagon
Pentagram Which shape is shown here?
Crescent
Cylinder
Cylinders are three-dimensional figures with two ends that are either circular or elliptical in shape. These are connected by a curved side.
Indalo
Taijitu Which shape is shown here?
Cardioid
Deltoid
Convex Hexagon
As with all hexagons, a convex hexagon has six sides. None of it internal angles can exceed 180 degrees. If this happens, the hexagon is concave.
Magatama Which shape is shown here?
Superellipse
Triangle
Rectoid
Triangular-based Pyramid
A triangular-based pyramid is a three-dimensional figure that consists of a base and three triangular sides. All of these are generally the same size, although they don't need to be. If they are, the pyramid is called a tetrahedron. Which shape is shown here?
Sphere
A sphere is a three-dimensional object that is perfectly round or symmetrical. This means that all points on the surface of the sphere are exactly the same distance from its center.
Circle
Pyramid
Rectangle n/a
Which shape is shown here?
Irregular Pentagon
A two-dimensional shapes with five sides. In an irregular pentagon, these sides, and the internal angles they produce, are unequal. The sum of all the angles on a pentagon is 540 degrees.
Circle
Decagon
Octagram Which shape is shown here?
Scalene Triangle
A scalene triangle, also called an irregular triangle, has three unequal sides and three unequal angles.
Normal triangle
Rhombus
Parallelogram Which shape is shown here?
Circumcircle
Trapezium
A trapezium is a quadrilateral with no parallel sides. This is a U.S. definition. In the U.K., it would be called a trapezoid.
Disc
Star polygon Which shape is shown here?
Star
Annulus
Hexagonal Prism
Essentially, a hexagonal prism is an octahedron. It features two bases, hexagonal in nature, and six rectangular sides. It is a three-dimensional shape.
Irregular Polygon Which shape is shown here?
Dodecagon
Nonagon
Octagon
Concave Hexagon
As with all hexagons, a concave hexagon has six sides. It will also have an angle that points back to it. Internal angles can exceed 180 degrees. Which shape is shown here?
Octahedron
An octahedron has eight sides. In its regular form, these are equilateral triangles. Essentially, this three-dimensional figure is two pyramids that are connected by their bases and stand 180 degrees to each other.
Decagon
Parralellogram
Rectangle Which shape is shown here?
Dodecahedron
A three-dimensional figure, a dodecahedron is a polygon with 12 faces. In the case of a regular dodecahedron, these faces take the form of 12 pentagons. It has 30 edges and 20 vertices.
Rhombus
Trapezium Which shape is shown here?
Parallelogram
Pentagon
Ellipse
Trapezoid
This quadrilateral has two sides that run parallel to each other. These are often referred to as the bases. The other two sides are not parallel and are called the legs. The distance between the two parallel sides is called the altitude. Which shape is shown here?
Segment
Cuboid
A cuboid is a three-dimensional shape where all the angles are 90 degrees formed by six flat sides. Cuboids are actually convex polyhedrons.
Sphere
Prism Which shape is shown here?
Digon
Henagon
Triangle
Square-based Pyramid
This three-dimensional figure has a square base and four equal triangles protruding upwards from that base. It also has five vertices and eight edges. Which shape is shown here?
Simple Polygon
Irregular Hexagon
A two-dimensional object with six sides, a regular hexagon has equal sides and internal angles, where an irregular hexagon will not. The internal angle is often more than 180 degrees, as two sides point back inside the hexagon.
Equiangular Polygon
Penrose Tile Which shape is shown here?
Octagon
An eight-sided polygon, an octagon in its regular form includes eight equal sides forming eight equal internal angles. If it is an irregular octagon, one or more angles will not be equal.
Pentagon
Square
Heptagon Which shape is shown here?
Kite
Ellipse
Concave pentagon
A concave polygon has two sides forming an internal angle. This also means that the angle is more than 180 degrees. This can only be achieved if the polygon has four sides or more.
Rhombus Which shape is shown here?
Icosahedron
An icosahedron has 20 faces. These take the form of equilateral triangles all joined together. This means a icosahedron has 30 sides and 12 vertices. If you look at a section of five of these equilateral triangles, you will see that they form a pentagon.
Balbis
Cyclic Polygon
Polyform Which shape is shown here?
Obtuse triangle
Constructible Polygon
Irregular Nonagon
Nonagons are two-dimensional shapes with nine sides. With a regular nonagon, all sides and internal angles are equal. With an irregular nonagon, sides may not be equal. This produces angles that are not equal and exceed 180 degrees. Which shape is shown here?
Concave Octagon
A concave octagon has two sides that form an internal angle leading to an irregular shape. This also means the angle is more than 180 degrees when measured.
Isosceles Triangle
Rectangle
Cylinder n/a
Which shape is shown here?
Pentagon
Trapezoid
Irregular Decagon
A two-dimensional shape with 10 sides. In an irregular decagon, these sides, and the internal angles they produce, are unequal. The sum of all the angles in a decagon is 1440 degrees.
Lens Which shape is shown here?
Decagram
Icosagon
Ellipsoid
This is a solid figure where all plane sections are made from circles or ellipses. The earth is shaped like an ellipsoid, and not a sphere, as was once thought. Which shape is shown here?
Dodecagon
Irregular Polygon
Arches
Rhombus
A rhombus can be defined in many ways. It is a equilateral, quadrilateral, or a parallelogram with equal sides. To easily recognize one, look for a diamond shape. All sides will be of equal length. Which shape is shown here?
Pentagonoid
Irregular Heptagon
Hepatgons are a form of a polygon but with seven sides. A regular heptagon has equal sides and angles. An irregular heptagon has different length sides and different angles sizes.
Lemoine Hexagon
Icosagon Which shape is shown here?
Nonagon
This is a 9-sided polygon with nine angles. It is also sometimes called an enneagon. All the angles within a nonagon add up to 1260 degrees.
Obtuse Triangle
Rhombus
Octagon Which shape is shown here?
Hexagon
Kite
A two-dimensional shape that has two sides that are pairs. The adjacent sides are also equal in length. All internal angles will always add up to 360 degrees. Two angles where the pairs meet will always be the same .
Pentagon
Diamond