Question

Use the cosine rule to calculate the size of angle x.
Give your answer to the nearest degree.

Answer 1

83.1

Explanation:

Using cos rule,

`\cos(x) = \frac{15 {}^(2) + 10 {}^(2) - 17 {}^(2) }{2 * 15 * 10} = (36)/(300) = (12)/(100)`

X = cos¯¹ 12/100 = 83.10789 = 83.1°

Answer 2

Just apply the formula and I hope this helps