cos ∠A = adj/hyp
∠A = cos⁻¹ (adj/hyp)
∠A = cos⁻¹ (10/15)
∠A = 48.2° (nearest tenth)
sin ∠B = opp/hyp
∠B = sin⁻¹ (opp/hyp)
∠B= sin⁻¹ (10/15)
∠B = 41.8°(nearest tenth)
a² + b² = c²
BC² + 10² = 15²
BC² = 15² - 10²
BC² = 125
BC = √125
BC = 11.2 units (nearest tenth)