Four angles of a pentagon add up to 440°. find the number of degrees in the fifth angle

There are 540 degrees in a pentagon so take 540-440=100
Fifth angle=100 degress

Okay so to find what all of the angles are supposed to add up to, you use the formula 180(n-2).

180 is what a straight line is.

So for a pentagon which has five sides, you subtract two (the number of sides are n in the equation). 

180(5-2)
180(3) = 540.

The sides should add up to 540 degrees.
If four of the sides already equal 440, subtract that from 540.

540-440=100.

The fifth angle is 100 degrees.

I hope that helps!