Use the law of cosines to find the measure of angle m to the nearest degree.

angle M = 47°

Step-by-step explanation:

By the law of cosine.

KL² = ML² + MK² - 2 (ML) (MK) cosM

Here KL = 15 ft.

        MK = 10 ft.

        ML = 20 ft.

Now we place the values in the formula

(15)² = (20)² + (10)² - 2(20)(10) cosM

225 = 400 + 100 - 400 cosM

225 - 500 - 400 cosM

225 - 500 = -400 cosM

-400 cosM = -275

cosM = = 0.6875

M = cos⁻¹ (0.6875)

   = 46.57° ≈ 47°

Therefore, angle M = 47°

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.