Question

estimate the measure of this angle within 15°.

Explanation:

Step1: Recall angle - size reference

A right - angle is 90°. This angle is larger than 90° but less than 180°.

Step2: Make an estimate

It looks to be around 135°. Since we need to estimate within 15°, a reasonable estimate could be 135° (the actual measure could be in the range 120° - 150°).

Answer:

135°