A rectangular cardboard is 10 decimeters long and 7 decimeters wide. How many circles can you cut from the paper with a radius of 1.5 decimeters?

A rectangular cardboard is 10 decimeters long and 7 decimeters wide. How many circles can you cut from the paper with a radius of 1.5 decimeters?

First, find the diameter of the circle 1.5 × 2 = 3
10÷3=3.1
7÷3=2.1
2 × 3 = 6

Cut out the biggest circle on a square sheet of iron with a side length of 4 decimeters. How many square decimeters is the remaining sheet area?

The diameter of the subtracted circle is 4 decimeters 4 * 4-3.14 * 2 * 2 = 3.44 square decimeters

Cut out two equal circles as large as possible from a rectangular sheet of 6 decimeters long and 3 decimeters wide. What is the area of the remaining sheet of iron in square decimeters?

Area = 6 × 3-2 × 1.5 × 1.5 × 3.14 = 3.87 square decimeter