Geometry Definitions PDF

Definitions Transversal- a line that passes through two lines in the same plane. Vertical angles- the angles across from each other where two lines cross. Linear pair- two angles next to each other that together make a straight angle. Supplementary angles- two angles that when added together eq...

Definitions Transversal- a line that passes through two lines in the same plane. Vertical angles- the angles across from each other where two lines cross. Linear pair- two angles next to each other that together make a straight angle. Supplementary angles- two angles that when added together equal 180 degrees. Complementary angles- two angles whose measures add up to 90 degrees. Alternate interior angles- The angles that are formed on opposite sides of the transversal and inside the two lines are alternate interior angles. Alternate exterior angles- a pair of angles that lie on the outside of two lines cut by a transversal, but on opposite sides of the transversal. Corresponding angles- angles that will be in the exact same place as the other line if you pick one line up and place it on top of the other. Consecutive exterior angles- a pair of angles formed when a transversal intersects two parallel lines, where both angles lie outside the parallel lines and on the same side of the transversal. Consecutive interior angles- a pair of angles formed when a transversal line intersects two parallel lines, where the angles are located on the same side of the transversal and are both inside the parallel lines. Congruent triangles- if all three corresponding sides are equal and all the three corresponding angles are equal in measure. Isosceles triangle- a triangle with two equal sides and angles. Equilateral triangle- a triangle with all three sides and angles of equal length. Scalene triangle- a triangle where all three sides are of different lengths and angles, meaning none of the sides are equal. Triangle Sum Theorem- if you add all three interior angles, they will add up to 180 degrees. Exterior Angle Sum Theorem- states that when a triangle's side is extended, the exterior angle formed is equal to the sum of the measures of the two opposite interior angles of the triangle. Vertex Angle- a point where two straight lines or rays meet. Base Angle- the angles formed at the "bottom" of the triangle and the base is considered as the bottom side. Hypotenuse- the longest side of a right triangle, which is always opposite of the right angle. Reflexive Property- a geometric figure is the same size and shape as itself; essentially, a figure is always equal to itself.