Mario cut a pizza into 9 equal slices. He put a slice on each of 5 plates. What is the measure for the angle of the slices that are left?

must be 4/9 of a circle left, or in degrees, 4/9 * 360

360 degrees

To find the measure of the angle of the slices that are left, we need to determine how many slices are left and divide the total angle of the pizza by that number.

First, we know that Mario cut the pizza into 9 equal slices. He put a slice on each of 5 plates, so 5 slices have been used.

To find out how many slices are left, we subtract the number of slices used from the total number of slices.
9 slices - 5 slices = 4 slices left

Now, we divide the total angle of the pizza by the number of slices left.
A whole pizza is typically defined as having a 360-degree angle. So, we divide 360 degrees by the 4 slices left.
360 degrees ÷ 4 slices = 90 degrees per slice

Therefore, the measure for the angle of the slices that are left is 90 degrees.