Term | Definition |
Geometry | The study of points lines angles surfaces and solids ? |
Point | A location in space represented by a dot? |
Line | A collection of points that extend forever in same direction? |
Line segment | A part of a line that has 2 end points ? |
Ray | A collection of points that begin at one point and extend forever ? |
Angle | 2 rays with the same end point ? |
Vertex | The point where 2 points meet? |
Plane | A flat surface that extends forever in all directions ? |
Parallel lines | Lines that are always same distance apart and will never cross each other? |
Intersecting lines | Lines that cross each other in the same spot ? |
Perpendicular lines | Intersecting lines that cross and make a right angle 90 degrees ? |
Acute angle | A angle less than 90 degrees ? |
Right angle | A perfect 90 degree angle ? |
Obtuse angle | A angle that is greater then 90 but less then 180 degrees ? |
Straight | A line that is flat 180 degrees? |
Reflex angel | A angle that is between 180 and 360 degrees ? |
Supplementary lines | 2 angles that equal to 180 degrees? |
Complementary lines | 2 angles that equal to 90 degrees |
Polygon | A closed plane figure with 3 or more sides triangle? |
Triangle | A polygon with 3 sides? |
Right triangle | A triangle with one 90 degree angle? |
Obtuse triangle | A triangle that has one angle that is bigger than 90? |
Acute triangle | All angles are less then 90 degrees |
Scalene triangle | A triangle with no equal sides? |
Isosceles triangle | A triangle with 2 equal sides ? |
Equilateral triangle | A triangle with all equal sides |
Quadrilateral | A polygon with 4 sides? |
Square | A polygon with 4 equal sides and 4 right angles? |
Rectangle | A 4 sided polygon with 4 right angles and 2 opposite angles are
Equal? |
Rhombus | A polygon with 4 equal sides and opposite angles are equal? |
Parallelogram | A 4 sided polygon with 2 equal and parallel sides? |
Trapezoid | A 4 sided polygon with one pair of parallel sides and one pair of
Sides that are not parallel ? |
Area | Number of square units needed to cover a region |
Perimeter | The add up,of all sides around a shape |
Area of square | Base x height |
Area of rectangle | B x h |
Area of triangle | 1/2 x b x h |
Area of Parallelogram | A = b x h |
Area of trapezoid | 1/2 x h ( b1 + b2 ) |
Altitude | Another word for height |