Question

In a figure, three adjacent angles on a straight line have measures x°, (2x + 10)° , and (x + 10)°. The measure

of the largest angle is ..................?

Answer 1

The three angles add to 180°: x + (2x+10) + (x+10) = 180 → 4x + 20 = 180 → x = 40°.
The angles are 40°, 90°, and 50°, so the largest angle measures 90°.