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If an equilateral triangle is a meter long, its circumference is () meters
3A
An equilateral triangle has a side length of two ninths of a decimeter. What is its circumference?
0
0
1 decimeter
As shown in the figure, the circumference of the three circles is 25.12 cm
Radius of circle: 25.12 ^ (2 × 3.14),
=25.12÷6.28，
=4 (CM);
Area of shadow part: 3.14 × 42 △ 2,
=50.24÷2，
=12 (square centimeter);
A: the shadow area is 25.12 square centimeters
As shown in the figure, the circumference of the circle is 25.12 cm, and the area of the circle is exactly equal to the area of the rectangle. How many centimeters is the length of the rectangle?
Radius of circle: 25.12 △ 3.14 △ 2 = 4 (CM),
Area of a circle (area of a rectangle)
3.14×42，
=3.14×16，
=24 (square centimeter);
The length of rectangle: 50.24 △ 4 = 12.56 (CM);
A: the length of this rectangle is 12.56 cm
As shown in the figure, given that the circumference of the circle is 25.12 cm, what is the area of the shadow part?
25.12 △ 3.14 = 8 (CM)
8 △ 2 = 4 (CM)
3.14×42×1
4-4×4÷2+8×4÷2
=12.56-8+16
=20.56 (square centimeter)
A: the shadow area is 20.56 square centimeters
The circumference of a circle is 25.12 cm. What is its diameter and area?
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14 = 8 (CM);
So the answer is: 8
The circumference of a semicircle is 25.12cm more than the diameter. Find the perimeter area
Let the radius be r
πR = 25.12
R = 8
Circumference of semicircle = π R + 2R = 41.12 cm
Area of semicircle = π R 2 / 2 = 100.48 square centimeter
The circumference of the semicircle is 25.7 cm. What is the area of the semicircle?
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