1. Triangles Find the value of x in the triangle. x + 78° + 56° = 180°
COURSE 2 LESSON 7-4
Triangles
Find the value of x in the triangle.
x + 78° + 56° = 180°
x + 134° = 180°
x + 134° – 134° = 180° – 134°
x = 46°
7-4

2. COURSE 2 LESSON 7-4
Triangles
Classify each triangle by its sides and by its angle measures.
Then find the measure of the missing angle.
18 in
6in
19°
11 in
isosceles; acute; 30°
This figure is not a triangle
Because = 17 and
17 < 18. The figure is not
closed, therefore is not a
Polygon (aka. Triangle)
7-4