# Geometry Vocab Ch 4

 Acute Triangle 3 acute angles Equiangular Triangle Three congruent acute angles Right Triangle One right angle Equilateral Triangle Three congruent sides Scalene Triangle No congruent sides Interior Angle formed by two sides of a triangle Exterior angle formed by one side of the triangle and the extension of an adjacent side. Each exterior angle has two remote interior angles Remote interior angle interior angle that is not adjacent to the exterior angle Corresponding angles + Corresponding sides the same position in polygons with an equal number of sides Congruent polygons (example) Two polygons are congruent polygons if and only if their corresponding angles and sides are congruent. Thus triangles that are the same size and shape are congruent Triangle rigidity provides a shortcut for proving two triangles congruent. (example) It states that if the side lengths of a triangle are given, the triangle can only have one shape Included angle Angle formed by two adjacent sides of a polygon Included side Common side of two consecutive angles in a polygon Angle-Side-Angle (ASA) If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent Hypotenuse-Leg (HL) If the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and a leg of another right triangle, then the triangles are congruent CPCTC - abbreviation for the phrase “Corresponding Parts of Congruent Triangles are Congruent.” Can be used as a justification in a proof after you have proven two triangles congruent Coordinate proof A style of proof that uses coordinate geometry and algebra. The first step of a coordinate proof is to position the given figure in the plane Legs shorter sides of a angle or triangle Vertex angle angle formed by the legs Base opposite side of the vertex angle Base angles two angles that have the base as a side AuthorDanielvu28 ID113515 Card SetGeometry Vocab Ch 4 DescriptionGuthrie Updated2011-11-01T00:56:30Z Show Answers