The measure of the acute angle for a right angle with a = 16.7 m and c = 81.4 m.

Find angle A. We can use the trigonometric function for sine to find angle A. $sinA=\frac{a}{c}$$sinA=\frac{16.7m}{81.4m}$$sinA=0.2052$ Now we solve for A by multiplying both sides of the equation by the inverse sine. So, $si{n}^{-1}(sinA)=si{n}^{-1}(0.2052)$$A=si{n}^{-1}(0.2052)$$A=11.8°$ Find angle B. We know that in right triangles the sum of the acute angles is 90°. So, $A+B=90°$ Solving for $B$, we get $B=90°-A$$B=90°-11.8°$$B=78.2°$