Question

estimate the measure of this angle within 10°.

Explanation:

Step1: Recall angle - size reference

A right - angle is 90°. This angle is less than 90°.

Step2: Make an estimate

It appears to be about two - thirds of a right - angle. Since $\frac{2}{3}\times90 = 60$, we estimate the angle to be 60° within 10°.

Answer:

60