Answer: The measure of angle A is 77.32°.
Step-by-step explanation: We are given to find the measure of angle A from the figure provided.
From the figure, we can note that
ΔABC is a right-angled triangle, where
∠B = 90°, AB = 18 units , BC = 80 units and hypotenuse AC = 82 units.
Therefore, from the laws of ratios of trigonometry we have
![\sin m\angle A=(perpendicular)/(hypotenuse)\\\\\\\Rightarrow \sin m\angle A=(80)/(82)\\\\\\\Rightarrow \sin m\angle A=0.9756\\\\\Rightarrow m\angle A=\sin^(-1)(0.9756)\\\\\Rightarrow m\angle A=77.3170^\circ\sim 77.32^\circ.](https://img.qammunity.org/2019/formulas/mathematics/college/8qngpyi186yza00zhfqgovovbuzgum5hg7.png)
Thus, the measure of angle A is 77.32°.