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About This Quiz

Basic shapes are one of the first things we get to learn about as a kid and let's be honest, it's pretty funny. You take a square block, try to fit it in a round hole and eventually you come to realize the two aren't the same and your brain clicks all of a sudden. Bam! You just figured out circles and squares. Then later in school they'll start teaching you about hexagons and parallelograms, you'll get the Pythagorean Theorem drilled into your head until you have triangle nightmares and you'll be able to tell someone what a rhombus is without even looking it up. Of course, the day may come when you drift away from geometry and start forgetting what you once learned. How many sides are in a dodecagon anyway? And what was the difference between an isosceles triangle and an obtuse triangle?

Lucky for you there are only so many shapes in the world at large so there are only so many options for a quiz like this, right? You know a circle when you see one. You know a rectangle like the back of your own hand! But do you know a great stellated dodecahedron? Let's find out!

Every point in this shape is an equal distance from its center. What is it?

Oval

Rhombus

Crescent

Circle

A perfect circle is one in which everything is equidistant from one middle point. Some people will get technical and say you can never draw a perfect circle because the line weight of the ink or whatever you drew it with will be inconsistent and imperfect, but that's nitpicking.

Which of these describes the shape of a common stop sign?

Hexagon

Octagon

A stop sign and a UFC fighting ring both have the same shape of an octagon. It's an 8-sided polygon, hence the "octa" part of the name. The sum of all internal angles in any octagon is 1080 degrees while the external angles add up to 360.

What do you call a triangle in which every angle is less than 90 degrees?

Obtuse

Right

Equilateral

Acute

Al three angles must be less than 90 degrees for a triangle to be considered an acute triangle. It's a kind of oblique triangle and cannot be a right triangle because none of the angles are exactly 90 degrees.

A pyramid is probably the most famous polyhedron shape thanks to the pyramids in Egypt. It has a polygon base and flat sides that meet at the apex or point on the top of the pyramid. The shape allows for very efficient weight distribution when it comes to building.

This is a quadrilateral with four even sides and angles. What is it?

Parallelogram

Rhomboid

Square

A perfect square has four sides of the same length and four even 90-degree angles. If the angles weren't even it could be slanted and become a parallelogram and if the sides aren't even but the angles are, then it's a rectangle.

If a triangle has one angle greater than 90 degrees it's which of these?

Scalene

Isosceles

Kepler

Obtuse

Acute refers to angles below 90 degrees while obtuse refers to those above. An obtuse triangle will still have two acute angles because mathematically that's the only possible way to join the shape with an obtuse angle.

Bees are crafty little creatures and they form their honeycombs in natural, six-sided hexagons. The shape also appears in nature in things like naturally forming basalt columns and in crystals like cinnabar and beryl.

Which three-dimensional shape often has a circle base that tapers to a point?

Cone

Cones taper smoothly from a flat base to a single apex point. The structure is one that allows for strength and stability focused on the point. One of the most prominent cones you'll see in nature is in a storm like a tornado.

Another name for which of these shapes is an equilateral quadrilateral?

Crescent

Icosagon

Cylinder

Rhombus

A rhombus is a shape that has four sides all of the same length. In very simple terms what we commonly understand as a diamond shape, as in the suit from a deck of playing cards, is a rhombus.

If every side of the triangle is a different length then it's which of these?

Equilateral

Scalene

All the measurements of a scalene triangle have to be different. No two sides share the same length, no two angles share the same number, either. A scalene could be a right triangle, but it doesn't have to be.

A three-dimensional shape with flat polygon faces is called what?

Paralleogram

Dodecagon

Polyhedron

When polygons meet the third dimension they become polyhedrons. A polyhedron has straight edges and sharp corners and comes from two Greek words "poly" meaning many and "hedron" meaning face.

Which of these shapes more or less resembles an egg?

Oval

You can play a little fast and loose with the rules of an oval as it's just any shape that tends to be egg-like. There are some more mathematical definitions of an oval when you start talking about things like a Cartesian oval or a Cassini oval.

If triskaidecagon reminds you of the word triskaidecaphobia, it's because both of them are based on the number 13. Phobia is fear of the number 13 while a triskaidecagon is a polygon with 13 sides.

Four straight but uneven sides and four right angles makes which of these shapes?

Prism

Rhombus

Rectangle

A rectangle is one of the simplest shapes in geometry and one of the most useful. Boxes, bricks and planks of wood are generally all made in a rectangular shape so they've definitely proven their worth at least in terms of construction.

If a triangle has one 90-degree angle, then it's one of which of these?

Right

By definition a right angle is a 90-degree angle, so a right triangle is a triangle with one 90-degree angle. If the length of the sides are integers, then it also qualifies as a Pythagorean triangle as well.

In technical terms you make a torus by "revolving a circle in three-dimensional space about an axis that is coplanar with the circle." In very simple terms it's a donut, or a three-dimensional ring. The plural is also tori, which is fun for anyone named Tori.

A kite is a quadrilateral shape with two distinct pairs of sides that are of equal length and adjacent to each other. Put in other terms, you have a long triangle with the base against the base of a shorter triangle to make a kind of a skewed diamond. You can also call it a deltoid if you want.

If two-dimensional is a square and three-dimensional is a cube, what's in the fourth dimension?

Tetrahedron

Megacube

Hypercube

A hypercube is what you call a four-dimensional shape analogous to a three-dimensional cube and a two-dimensional square. It's also known as a tesseract which you might remember from the "Avengers" movies. A cube has six square surfaces while a hypercube has eight cubed cells.

The US Department of Defense made its headquarters in which shape?

Pentagon

The Pentagon is named for its five-sided shape, a pentagon. Though the shape does have an artificial quality to it, you can find it frequently in nature. For instance, if you cut a cross-section of okra it will be in a pentagon shape, and flowers like morning glories bloom in a pentagonal shape as well.

What's the name for a right triangle in which each side follows in a geometric progression where the common ratio is the root of the Golden Ratio?

Scalene

Pythagorean

Kepler

The squares of the sides of a Kepler triangle are in geometric progression according to the Golden Ratio. What's the Golden Ratio? Tha's what happens when the ratio of two quantities is the same as the ratio of their sum to the larger of the two quantities.

They call a quadrilateral with two pairs of parallel sides what?

Equialteral

Hexagram

Parallelogram

It makes sense that a parallelogram is defined by parallel sides. The opposing sides are of equal length and it's officially a rhomboid. It can't have a right angle or it'd be either a square or a rectangle.

If a shape has 12 faces on it, it's a dodecahedron. They come in a few varieties but a regular dodecahedron has 12 faces, 20 vertices, 30 edges, and 160 diagonals. It's a pretty common shape for dice in games like "Dungeons and Dragons."

A polyhedron with two parallel bases or faces and all other faces being parallelograms is called what?

Megagon

Rhombus

Cylnder

Prism

In a non-geometrical way, a prism is just a transparent piece of glass or plastic that can refract light. In geometry it's any polyhedron shape connected with an identical shape by parallelograms on the corresponding sides. The base can be any shape like a pentagon or a hexagon.

Canadian one dollar coins are in which of these shapes?

Tetrahedron

Nonagon

Hendecagon

A hendecagon is an 11-sided polygon that can sometimes go by the name undecagon or endecagon, though those aren't the best choices since they merge Greek and Latin. The internal angles of a hendecagon add up to 147 and 3/11 degrees in total.

When two sides of a triangle are of equal length what is it called?

Scalene

Acute

Obtuse

Isosceles

At least two sides of an isosceles triangle have to be the same length but not all three sides. That said, all three sides could be and that would make it an equilateral triangle and technically a different shape altogether.

Pentagrams are sometimes called pentangles or pentalphas. They've been a popular shape throughout history used in ancient Sumerian cuneiform, Ancient Greece, Wicca symbolism and also associated with Satanism.

A megagon is the sort of shape you can't really draw and only exists in theory or computer models. With one million sides, if you were to draw one the size of the Earth itself it would still look like a perfect circle.

You might also use this word to describe a cough drop. What is it?

Lozenge

A lozenge can be a straight synonym for a rhombus, which is what is often referred to as a diamond. But usually, to distinguish it from a rhombus, it refers to a thin kind of rhombus with two acute and two obtuse angles.

Four edges and four corners define which of these shapes in Euclidean plane geometry?

Tetrahedron

Hexagon

Axis

Quadrilateral

Quadrilateral is a very basic term for a four-sided shape which can include squares, rectangles, parallelograms, kites or other irregular shapes. As long as they have four sides they qualify for the label.

The internal angles in which of these shapes total 144 degrees?

Trapezoid

Decagon

A decagon is a ten-sided polygon which, in a pinch, you can call a 10-gon. It's not a shape that gets used for many things, though you can find dinner plates or mirrors that are made in decagonal shapes now and then.

A cardboard box with even sides is this shape. What is it?

Tetrahedron

Cylinder

Cube

A cube is a very simple shape, the three-dimensional representation of a square with six even and identical faces. As far as three-dimensional shapes go, it's one of the most commonly used for blocks, boxes and tons of other things. Even salt naturally forms in cubes.

The 20-sided icosagon has internal angles that add up to 162 degrees. You may not have realized it but the Big Wheel on "The Price is Right" is an icosagon, meaning that geometry can really be worth something one day!

Some people call which of these a triangular pyramid?

Tetrahedron

A pyramid with a triangular base is also known as a tetrahedron. It has four triangular faces and six straight edges. It's the simplest kind of convex polyhedron and the only one that has fewer than five faces.

A basketball is essentially which of these shapes?

Oval

Sphere

A sphere is a three-dimensional representation of a circle. For a sphere to be perfect mathematically, every point on the surface has to be equidistant from the center. Planets and atoms are examples of spheres in nature.

The crescent shows up a lot throughout history. Because of the way lunar cycles work, the crescent moon is the most prominent example but it's also used as a symbol for Islam and, very often, the shape croissants are baked in.

A quadrilateral with at least one pair of parallel sides is called what?

Pentangle

Prism

Lozenge

Trapezoid

A trapezoid is what you call this shape in North America but the rest of the world knows it as a trapezium. The sides can't be of equal length or otherwise you'd have a square plus two sets of parallel sides.

Every side of which kind of triangle is an equal length?

Oblique

Pythagorean

Equilateral

All three sides of an equilateral triangle are of the same length. That in turn means that all the angles are equal at 60 degrees each. You can call this a regular triangle as well, and like many shapes it's a polygon.

Twelve intersecting pentagrammic faces make what shape?

Convex regular dodecahedron

Triakis icosahedron

Great stellated dodecahedron

Most people will never run across a great stellated dodecahedron. Much the same as a square is analogous to a cube and a circle is analogous to a sphere, a pentagram is analogous to the great stellated dodecahedron.

A cylinder is a pretty handy shape for holding things like Pepsi or beans, which is why so many cans are made as cylinders. It is essentially a circular prism. Cans are made in that shape because a cylinder is one of the most structurally sound shapes that exist.

Do you know what you'd call a polygon with infinite sides?

Infinigon

N-gon

Apeirogon

This is one of those weird theoretical shapes that you're certainly never doodling on a napkin. It's still different from a circle which would have an infinite number of points that aren't necessarily sides, like what an apeirogon would have.