Question

Given: ΔABC; b= 10; c = 14, and ∠A = 54°. Find the length of side a to the nearest whole number.

Answer 1

A² = b² + c² - 2bc cosA
a² = 10² + 14² - 2*10*14 cos54
a² = 100 + 196 - 280 * cos54
a = $\sqrt{100 + 196 - 280 * cos54}$
a = 11.46