- Quadrilateral– any four-sided shape
- 2-dimensional– has only length and width, lays flat
- Edge– any side of the shape
- Vertices– corner of the shape where two edges meet
- Parallel– always the same distance apart and never touching
- Right angle– 90°
- Rectangle– four-sided shape where every angle is a right angle and opposite sides are parallel
- Rhombus– a four-sided shape where all sides have equal length, opposite sides are parallel, and opposite angles are equal
- Square– a four-sided shape that has equal sides, every angle is a right angle, and opposite sides are parallel
- Parallelogram– four-sided shape where opposite sides are parallel and equal in length, and opposite angles are equal
- Trapezoid– a four-sided shape that has a pair of opposite sides parallel
- Kite– a four-sided shape with 2 pairs of equal sides next to each other
- Radius– The distance from the center to the edge
- Circumference– the distance around the edge of the circle
- Diameter– starts at one side of the circle, goes through the center and all the way to the other side of the circle
- Center– the point inside a circle where every point on the line of the circle is equal distance from
- Circle– a set of points that are all a fixed distance from the center
- Chord– a line that goes from one point to another point on the circle but does not pass through the center
- Tangent– a line that just touches the circle at one point and that is on the outside of the circle
- Arc– a small part of the circumference
- Semicircle– a circle that is cut in half
- Triangle– has three sides and three angles
- Equilateral triangle– three equal sides and three equal angles
- Isosceles triangle– two equal sides and two equal angles
- Scalene triangle– no equal sides and no equal angles
- Acute– angle is less then 90°
- Right – angle is 90°
- Obtuse – angle is more than 90°
- Three dimensional-has three dimensions: width, depth, and height
- Face– any individual surfaces on a solid object
- Vertex (plural: vertices) -is a corner or a point where two or more straight lines meet
- Edge– a line segment that joins two vertices
- Cross section– the shape you get when cutting straight across an object
- Prism– has the same cross section all along its length
- Pentagon– a five sided shape
- Cube– has 6 faces that are all squares
- Cuboid– has 6 faces that are rectangles
- Pyramid– a three dimensional shape that has a polygon as its base and triangles as its other faces that all meet at a common vertex
- Apex– the vertex where all triangle faces meet in a pyramid
- Sphere– all points on the surface are the same distance from the center
- Cylinder– has a flat top and a flat bottom and one curved side
- Cone– has a flat bottom and an apex with a curved side
- Base– the flat bottom and/or top on a pyramid, cylinder and cone
From Georgia Virtual Learning