Angles of Triangles 4.2
Angle Sum Theorem – The sum of the measures of the angles of a triangle is 180°. Thm - If two angles of one triangle are ≅ to two angles of a second triangle, then then the third angles are ≅
Exterior angle – formed by one side of a triangle and the extension of another side. 1 Remote Interior angle – the interior angles of the triangle that are NOT adjacent to the exterior angle.
Exterior Angle Thm – The measure of an exterior < of a triangle is equal to the SUM of the remote interior angles. Thm – The acute angles of a right triangle are complementary. Thm – There can be at most one right or one obtuse angle in a triangle.