Question

For Tran Please help is appreciate it

Answer 1

A = 38°

Explanation:

We are going to use cosine law to find angle A where

a = 4.7

b = 3.9 m

c = 2.9 m

`{c}^(2) = {a}^(2) + {b}^(2) - 2ab \cos( \alpha )`

or

`\cos( \alpha ) = \frac{ {a}^(2) + {b}^(2) - {c}^(2) }{2ab}`

cos A = [(4.7)^2 + (3.9)^2 - (2.9)^2]/2(4.7)(3.9)

= 28.89/36.66

= 0.788

A = arccos(0.788) = 38°