find m∠a. write your answer as an integer or as a decimal rounded to the nearest tenth. m∠a = °

Explanation:

Step1: Recall trigonometric ratio

In right - triangle (ABC) with right - angle at (B), we use the sine ratio. (\sin A=\frac{BC}{AC}).

Step2: Identify side lengths

Given (BC = 4) and (AC = 10). So, (\sin A=\frac{4}{10}=0.4).

Step3: Find the angle

We know that if (\sin A = 0.4), then (A=\sin^{- 1}(0.4)). Using a calculator, (A=\sin^{-1}(0.4)\approx23.6^{\circ}).

Answer:

(23.6)