A road sign is in the shape of a regular pentagon. What are the measure of each angle on the sign

A triangle has 180° and a quadrilateral (4 sides) has 360°. For each additional side we add 180° so a 5 sided figured has 360 + 180 = 540° total. 540/5 (5 sides) = 108° per angle.

Formula for any number of sides where s is the number of sides = (s-2) 180°

Let's try if for 3 sides (3-2) 180 = 1 (180) = 180°

Now four sides (4-2) 180 = 2 (180) = 360°

And finally, your pentagon = (5-2) 180 = 3 (180) = 540°

and 540 shared equally in a regular pentagon (regular means all sides and angles are the same) means 108 degrees in each angle 540:5 = 108°

Pentagon has five sides

5-2=3

3times 180 is 540

540 is total angles

540 divided by 5 is 108