Question

What dose this = to? triangles = to 180 buts all i know

Answer 1

7. Straight lines are also = to 180°

If you look at the diagram, when you add the two angles together, they form a straight line.

Since the angles add up to 180°, you can do:

(x + 25)° + (4x + 5)° = 180°

x + 25 + 4x + 5 = 180        Combine like terms

5x + 30 = 180         Subtract 30 on both sides

5x = 150       Divide 5 on both sides

x = 30