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A circle with a radius of 2.5cm is equal to the perimeter of a rectangle. It is known that the length of the rectangle is 4.5cm. What is the area of the rectangle?
The circumference of the circle is 2 * 2.5 * 3.14 = 15.7 (CM), the width of the rectangle is 15.7 / 2-4.5 = 7.85-4.5 = 4.35 (CM), and the area of the rectangle is 4.5 * 4.35 = 19.575 (cm ^ 2)
The perimeter of the rectangle is 20cm, and the length and width are increased by 5cm. What is the area?
20 △ 2 * 5 + 5 * 5 = 75 square centimeter
Add 75 square centimeters
This is the first answer. I wish you progress!
A corner of a 20cm square paper, cut a rectangle 13cm long and 5cm wide, what is the perimeter of the remaining paper
20*4=80
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