The circle is 15 cm high and 10 cm in diameter. How many square meters is the area

Circle? And height? You mean cylinder? Cylinder area = bottom area * height = 3.14 * (10 / 2) ^ 2 * 15 = 3.14 * 25 * 15=

A roller is 2.5 meters long and 2 meters in diameter. If it rolls 10 times, how many square meters is the roller area?

Roller drum diameter is 2 meters, its circumference is:
2 × 3.14 = 6.28 (m)
The roller is 2.5m long, so the roller area for rolling one cycle is as follows:
6.28 × 2.5 = 15.7 (M2)
If rolling for 10 cycles, the roller area is:
15.7 × 10 = 157 (M2)

Two round flower beds with a diameter of 10 meters have been built in the campus. How many square meters is the area of flower beds? How to calculate

The flower bed covers an area of 2 × 3.14 × (10 / 2) &# 178; = 157 square meters
Methods: according to the area formula of circle

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