# If You Can Name All of These Shapes, You'd Totally Pass a 9th-Grade Math Class

By: Kennita Leon
Image: Original

A shape is a form that outlines the boundaries of an object. For centuries now, humans have used shapes to for a multitude of reasons. The most commonly used ones are known as geons.

Geons are 2D and 3D shapes that include cylinders, cones, rectangles and circles. They are made up of curves, angles, lines and sometimes, patterns and can be found all around you. You can find these shapes in nature on leaves, in architectural structures and on the human body.

Now, a lot of these shapes, particularly the geometric ones, are used in mathematics and everyday life. When it comes to math, they are used in geometry, the branch of math that is concerned with points, surfaces and lines, or the study of space and shapes.

Because shapes are the foundation of this particular branch of math, we want to test your knowledge of them today. We're going to give you every shape we know of, from the simple ones like the circle and the square, to the more complicated ones like the pentagram, annulus and ellipse. Your job is to correctly identify the shape in each picture. If you pass this test, you'll have no problem with 9th-grade math. So let's see if you're up to the challenge.

An oval is described as a closed curve in a two-dimensional plane which resembles the outline of an egg.

This type of triangle is characterized by its three sides, two of which connect to form a 90-degree angle.

A trapezoid, of which there are several types, is defined as a quadrilateral shape with one pair of parallel sides.

A dodecagon, also called a 12-gon, is any 12-sided figure which typically features 12 angles of the same size and 12 sides of the same length.

A parallelogram is illustrated as a quadrilateral with two pairs of parallel sides which may or may not be of equal length.

This shape, which is associated with several meanings, is commonly used to represent the first quarter lunar phase of the moon.

An ellipse is a closed curve on a flat surface encompassing two focal points which remains the same for every point on the curve.

Rectangles are identified as parallelograms or quadrilaterals with two pairs of sides of differing lengths and four right angles.

This symbol, which is usually colored red, is used to express romantic emotions such as love and affection.

An obtuse triangle is one which features an angle greater than 90 degrees and two which measure less than 90 degrees.

A circle, which may also be considered a special type of ellipse, is a simple, round plane figure connected by a single line.

Cuboids are described as a 3-D version of a rectangle with six quadrilateral sides that are referred to as faces.

This three-dimensional shape is composed of five faces, two of which are triangles and the other three are rectangles.

A rhombus, which resembles a diamond, is any quadrilateral with four parallel sides of the same length and opposite, equally-sized obtuse and acute angles.

The typical star shape, also called the star pentagon, consists of two sets of five vertices or points and ten edges.

This type of 3-D pyramid differs from the other variants in that it is constructed using a square as the base.

A square is defined as a type of quadrilateral that comprises of four equal sides and four right angles.

The lens, in two-dimensional geometry, is described as a convex shape that is joined at the end of two outwardly curved arcs.

An equilateral triangle is one in which all three sides, and all internal angles, are of the same length and size.

This type of polygon, also known as the 10-gon, is composed of ten sides and angles of equal length and size.

A cube is the three-dimensional solid version of the square which is bounded by six equally sized faces, sides or facets.

Also known as the triangular pyramid, the tetrahedron is a 3-D solid shape with four triangular faces, four vertices and six straight edges.

The annulus, which is Latin for "little ring," is the mathematical term for a circle with a circular hole in the middle, kind of like a donut.

The nonagon is a polygon composed of nine sides of equal length as well as nine equally sized angles.

This geometric figure is described as a three-dimensional solid shape with two parallel straight lines and two oval or circular cross-sections.

This quadrilateral shape consists of two pairs of straight lines which are of equal length and are adjacent to each other.

The octagon is a type of polygon with eight equal sides, vertices and angles, that add up to 1,080 degrees.

A cone, which may be solid or hollow, is a 3-D geometric shape with a single point that tapers down to a flat, round base.

An isosceles triangle is a specific type of triangle that is usually made up of two equal sides and angles.

The frustum is a geometric shape that is formed by cutting across horizontally the top of a cone or pyramid.

This figure, which is a type of polygon, is composed of seven sides and angles of the same length and size.

An ellipsoid is the three-dimensional solid version of the ellipse with a circular or ellipse cross-section.

This 3-D shape is a polyhedron that is characterized by its eight facets, twelve edges and six points.

This variant of the pyramid is composed of three triangular faces and one square that forms the base.

A trapezium is a type of quadrilateral that is characterized by four non-parallel sides of unequal lengths.

A hexagon, also known as a 6-gon, is a six-sided polygon with six equally-sized angles that add up to 720 degrees.

This figure is a perfectly round shape that is the three-dimensional equivalent of the two-dimensional circle.

A scalene triangle is used to describe triangles with three sides of different lengths and comparably three angles of varying sizes.

A pentagon, which may be simple or self-intersecting, is a five-sided polygon with five internal angles that add up to 520 degrees.

A deltoid, also referred to as a Steiner curve or tricuspid, is a triangular shape connected by three inward curves.