In the picture below, if the measure of ∠1 is (2x + 10)º, the measure of ∠2 is (5x - 40)º, and the measure of ∠4 is 60 degrees, find the actual angle measures of ∠1, ∠2, and ∠3.

Extra: If we don't know that the measure of ∠4 is 60 degrees, can we still determine anything about the measure of ∠3? Why or why not?