Question Analysis
This question focuses on using inverse trigonometric functions to find the measure of angle in a right - triangle. We need to identify the appropriate trigonometric ratio based on the side lengths relative to angle and then use the inverse trigonometric function to calculate the angle.
Key Concept Explanation
In a right - triangle, for an acute angle :
, , .
The inverse trigonometric functions , , are used to find the angle when the ratio of the sides is known. For example, if , then ; if , then ; if