1. Triangles
7.3

2. Classification by sides
Equilateral has all sides congruent
Isosceles has 2 congruent sides
Scalene has no congruent sides

3. Classification by Angles
Acute has 3 angles less than 90°
Right triangle has 1 angle = 90 °
Obtuse has 1 angle greater than 90 °
Equiangular: has 3 congruent angles (is also acute)

4. Right, Scalene Triangle

5. Right, Isosceles Triangle

10. Triangle Sum Theorem The sum of the measures of the interior angles of a triangle is 180°.B
mA + mB +mC = 180° A C

11. Find m<E in triangle DEF if m<D= 62 degrees and m<F= 39 degrees.

12. Page 286 (6-13) all Page 288 (1-6) all
Homework
Page 286 (6-13) all Page 288 (1-6) all