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A rectangular piece of paper is 20 cm long. Cut the largest square from one end. What is the circumference of the remaining rectangle? For the formula, please hurry up
Suppose the width of a rectangle is a
(20-a + a) × 2 = 20 × 2 = 40 (CM)
A: the perimeter of the remaining rectangle is 40 cm
Absolutely right!
A piece of rectangular paper is 10 cm long and 6 cm wide. After cutting a square (as shown in the figure), what is the circumference of the remaining figure? （ ）
A. 32 cm B. 24 cm C. 20 cm
(10-6 + 6) × 2, = 10 × 2, = 20 (CM); answer: the perimeter of the remaining figure is 20 cm
In a 20 cm long and 16 cm wide rectangular paper, check out the largest semicircle. What is the perimeter of the remaining figure of the rectangle?
It's perimeter
The semicircle with length as diameter is the largest
So the rest of the perimeter is
20+16×2+20×3.14÷2
=20+32+31.4
=83.4
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