Question

1. estimate the measure of ∠lmn to the nearest 10°

Explanation:

Step1: Identify angle type

The angle is acute (less than $90^\circ$), closer to $45^\circ$ than $0^\circ$ or $90^\circ$.

Step2: Estimate to nearest $10^\circ$

Compare to reference angles: it is near $40^\circ$ (or $50^\circ$; $40^\circ$ is a reasonable estimate as it is less than a right angle's half, ~$45^\circ$).

Answer:

$40^\circ$ (or $50^\circ$; a reasonable acute angle estimate rounded to the nearest $10^\circ$)