Question

estimate the measure of this angle within 15°.

Explanation:

Step1: Recall angle - type knowledge

An acute angle is less than $90^{\circ}$.

Step2: Make an estimate

Compare with common angles. A $45^{\circ}$ angle (half of a right - angle) and a $60^{\circ}$ angle (from an equilateral triangle divided by a height). The given angle looks closer to $60^{\circ}$ than to $45^{\circ}$ or $75^{\circ}$ (since $60 - 45=15$, $75 - 60 = 15$).

Answer:

$60^{\circ}$