Geometry Practice Test 6

$\frac{1}{2}$ ∠A + $\frac{1}{3}$ ∠C + $\frac{1}{2}$ ∠B = 80°
$\frac{\angle \mathit{C}}{3}$ = 80° - $\frac{1}{2}$ (∠A + ∠B)
∠C = $3\left(80°-\frac{1}{2}\angle \mathit{A}+\angle \mathit{B}\right)$
∠C = 240° - $\frac{3}{2}$ (∠A + ∠B)
∠C = 240° - $\frac{3}{2}$ (180° - ∠C)
(Since ∠A + ∠B + ∠C = 180° , ∠C = 180° - (∠A + ∠B))
∠C = 240 - 270 + $\frac{3}{2}$ ∠C
∠c - $\frac{3}{2}$ ∠C = - 30
- $\frac{\angle \mathit{C}}{2}$ = - 30
∠C = 60°