The measure of the angle ∠4 is 59°.
How to find the measure of angle 4?
The sum of the 3 angles near angle 4 should be a plane angle (angle with a measure of 180°). Then we can write the equation:
m∠4 + 60° + 61° = 180°
Now we can solve this equation for the measure of angle 4, we will get:
m∠4 = 180° - (60° + 61°)
m∠4 = 180° - 121°
m∠4 = 59°
That is the measure.