Solve the triangle. B = 73°, b = 15, c = 8, find the remaining side.
Two important laws to find the missing side or angle of a triangle are the sine and cosine rules.
Answer: The value of the unknown side of the triangle is 15.22 units.
Go through the solution to understand better.
Given, B = 73°, b = 15, c = 8.
Applying the cosine rule:
b2 = a2 + c2 - 2ac cos B
(15)2 = (a)2 + (8)2 - 2a(8) cos 73º
225 = a2 + 64 -16a × 0.29
0 = a2 - 4.64a - 161
On solving the quadratic equation using Cuemath's quadratic calculator, we get:
a = 15.22