# Geometry Terms

• 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

http://cms.gavirtualschool.org/Shared/Math/MSMath7/GeometricShapes/Math7BUnit2Introduction_Shared/index.html