Question

estimate the measure of this angle within 15°.

Explanation:

Step1: Recall angle - type knowledge

An acute angle is less than 90°. This angle is clearly acute. A 30° angle is relatively small, a 45° angle has the two sides in a 1:1 - like ratio in a right - triangle context, and a 60° angle is larger among acute angles. This angle looks close to 45°.

Answer:

45