Finding the Area of a Square or Rectangle Here is a rectangle. The area is all the space inside the rectangle. To find the area follow the steps 10cm 5cm 1. Find or Measure the length along the bottom of the rectangle. In this case it is 5cm. 2. Find or Measure the height of the rectangle. In this case it is 10cm. 3. Finally Multiply these two numbers. So do 5 times 10 =