Question

estimate the measure of this angle within 10°.

Explanation:

Step1: Recall angle - type knowledge

A right - angle is $90^{\circ}$.

Step2: Observe the given angle

The given angle is larger than a right - angle.

Step3: Make an estimate

It seems to be about $100^{\circ}$ within the $10^{\circ}$ tolerance.

Answer:

$100^{\circ}$