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Math geometry vocab
Term | Definition |
---|---|
Acute triangle | A triangle that measures 89 degree or less. |
Adjacent angles | Two angles that share a common vertex, common side, and do not overlap. |
Base | A prism with at least one of the two parallel congruent faces. |
Center | The middle of the circle. |
Circle | The set of all points in a plane that are the same distance from a given point called the center. |
Circumference | The distance around the circle. |
Complementary angles | Two angles that will equal 90 degree. |
Composite figure | A figure made up of 2 or more shapes. |
Cone | A figure with a circular base connected by a curved side to a single vertex. |
Congruent | Vertical angles that have the same measure. |
Congruent segements | Sides of a triangle with the same length. |
Coplanar | Lines or planes that are connected. |
Cross sections | The intersection of a solid and a plane. |
Cylinder | A 3-D figure with two parallel congruent circular bases connected by a curved surface. |
Diagonal | A line segment that connects two nonconsecutive vertices. |
Diameter | The distance across a circle through it's center. |
Edge | The line segment where two faces of a polyhedron intersect. |
Equilateral triangle | A triangle having three congruent sides. |
Faces | A flat surface of a polyhedron. |
Isosceles triangle | A triangle with at least two congruent sides. |
Lateral face | Any flat surface that is not a base. |
Lateral surface area | The sum of the areas of the lateral faces of a solid. |
Obtuse triangle | A triangle with one obtuse angle (obtuse angle=91+ degree. |
Pi | The ratio of the circumference of a circle to it's diameter. The Greek letter PI represents this number. The value is 3.1415926... or 3.14 or 22/7. |
Plane | A 2-D flat surface that extends in all directions. |
Polyhedron | A 3-D figure with faces that are polygons. |
Prism | A polyhedron with two parallel congruent faces called bases. |
Pyramid | A polyhedron with one base that is a polygon and three or more triangular faces that meet at a common vertex. |
Radius | The distance from the center of a circle to any point on the circle. |
Regular Pyramid | A pyramid whose base is a regular polygon and in which the segment from the vertex to the center of the base is the altitude. |
Right triangle | A triangle having one right angle. |
Scale model | A model used to represent objects that are too large or too small to be built at actual size. |
Scalene triangle | A triangle having no congruent sides. |
Semicircle | Half of a circle. |
Slant height | The height of each lateral face. |
Supplementary angles | Two Angles that add up to 180 degree. |
Surface area | The sum of the areas of all the surfaces (faces) of a 3-D figure. |
Triangle | A figure with three sides and three angles. |
Vertex | The common endpoint of the rays forming the angle. |
Vertical angles | Opposite angles formed by the intersection of two lines. |
Volume | The measure of the space occupied by a solid. |