if a wire is bent into the shape ofa square is 49cm .when the wire is bent into a semi circular shape,find the radius of semi circle
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Answered by
9
Length of the wire = 49 cm
Define x:
Let the radius be x
Circumference of a semicircle
Circumference of a semicircle = 2r + 1/2(2πr)
Circumference of a semicircle = 2r + πr
Find the radius:
2r + πr = 49
r(2 + π) = 49
r = 49 ÷ (2 + π)
r =9.53 cm
Answer: The radius is 9.53 cm
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1
☺☺☺here is Your answer OK ....⛪⛪
Area of square = 81 cm²
=> Side= 9 cm
=> Perimeter = 9 x 4 = 36 cm
If this is bent into semicircle of radius r, perimeter = πr + 2r
=> r(π+ 2) = 36
You get value of r from here
A little birdie tells me r = 7 cm
Substitute this value in area formula:
Area = ½ x πr²
OK this step you do..
Area of square = 81 cm²
=> Side= 9 cm
=> Perimeter = 9 x 4 = 36 cm
If this is bent into semicircle of radius r, perimeter = πr + 2r
=> r(π+ 2) = 36
You get value of r from here
A little birdie tells me r = 7 cm
Substitute this value in area formula:
Area = ½ x πr²
OK this step you do..
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