1. Classifying Triangles www.pleasanton.k12.ca.us/.../Powerpoints/4.1_Triangles_and_Angle...

2. Equilateral 3 congruent sides Isosceles At least 2 congruent sides Scalene No congruent sides

3. Equilangular 3 congruent angles Acute 3 acute angles Obtuse 1 obtuse angle Right 1 right angle

4. Vertex: the point where two sides of a triangle meet  Adjacent Sides: two sides of a triangle sharing a common vertex  Hypotenuse: side of the triangle across from the right angle  Legs: sides of the right triangle that form the right angle  Base: the non-congruent sides of an isosceles triangle

5. Label the following on the right triangle:  Vertices  Hypotenuse  Legs Vertex Hypotenuse Leg

6. Label the following on the isosceles triangle:  Base  Congruent adjacent sides  Legs m<1 = m<A + m<B Adjacent side Base Adjacent Side Leg

7.  Interior Angles: angles inside the triangle (angles A, B, and C) A B C 1 2 3 Exterior Angles: angles adjacent to the interior angles (angles 1, 2, and 3)

8.  The sum of the measures of the interior angles of a triangle is 180 o. A B C <A + <B + <C = 180 o

9.  The measure of an exterior angle of a triangle is equal to the sum of the measures of two nonadjacent interior angles. A B 1 m<1 = m <A + m <B

10.  The acute angles of a right triangle are complementary. B A m<A + m<B = 90 o www.pleasanton.k12.ca.us/.../Powerpoints/4.1_Triangles_and_Angle...