In angle ABC, AB = 2.5 m, BC = 3.2 m and AC = 2.9 m. Use the Cosine Law to find
, to the nearest degree.

9514 1404 393
Answer:
∠A ≈ 72°
Step-by-step explanation:
Fill in the given numbers and do the arithmetic.
cos A = (2.9² +2.5² -3.2²)/(2(2.9)(2.5)) = 4.42/14.5
The inverse cosine function is used to find the angle, given its cosine.
A = arccos(4.42/14.5)
∠A ≈ 72°