# How do you use what you know about triangles to find the measure of third angle A=23^circ, B=86^circ, C=x?

We use the knowledge that sum of the angles of a triangle is ${180}^{\circ}$ to find e measure of third angle and $\angle C = {71}^{\circ}$
We use the knowledge that sum of the angles of a triangle is ${180}^{\circ}$ to find e measure of third angle.
As $\angle A = {23}^{\circ}$ and $\angle B = {86}^{\circ}$
$\angle C = {180}^{\circ} - {23}^{\circ} - {86}^{\circ} = {71}^{\circ}$