Question

The second angle of a triangle is twice as large as the first angle. The third angle is 35 greater than the second angle. How large is the first angle?

Answer 1

29°

Explanation:

Let x represent the first angle. Then the second angle is 2x, and the third angle is 2x+35°. The sum of the angles is 180°, so we have ...

x + 2x + (2x+35) = 180

5x +35 = 180 . . . . collect terms

x +7 = 36 . . . . . . . divide by 5

x = 29 . . . . . . . . . . subtract 7

The first angle is 29°.