## Geometry: Common Core (15th Edition)

The third angle is $58^{\circ}$.
The measures of the three angles of a triangle equal $180^{\circ}$; therefore, if we have the measure of two angles, we can figure out the measure of the third angle. $34 + 88 + x = 180$ Add the constants on the left side together: $122 + x = 180$ Subtract $122$ from each side to solve for $x$: $x = 58$ The third angle is $58^{\circ}$.