Geometry Terms

  • 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

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