Question

estimate the measure of ∠abc. there are many challenges on this screen. degrees check my estimate

Explanation:

Step1: Compare to right angle

A right angle is $90^\circ$. $\angle ABC$ is smaller than a right angle, larger than $0^\circ$.

Step2: Estimate the angle

Visually, the angle is roughly $\frac{2}{3}$ of a right angle.
$\frac{2}{3} \times 90^\circ = 60^\circ$

Answer:

60 degrees