from a circular sheet of paper of radius 25 cm,a sector area 4% is removed.if the remaining part is used to make a conical surface,then the ratio of the radius and height of the cone is what?
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Answered by
21
angle of the cutout section = 4/100 *360 = 14.4 degrees
leftover perimeter = 96/100 * 2π * 25 = 48π
radius of cone bottom = 48π/2π =24 cm
sloping side of cone= radius of the original piece= 25
height² = 25²-24² =625 - 576
= 49
height= 7 cm
radius:height =24:7
leftover perimeter = 96/100 * 2π * 25 = 48π
radius of cone bottom = 48π/2π =24 cm
sloping side of cone= radius of the original piece= 25
height² = 25²-24² =625 - 576
= 49
height= 7 cm
radius:height =24:7
myinbox3shiv:
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Answered by
13
SEE Diagram
when circular area of r =25cm is folded into a cone, the lateral length L of cone is = 25cm. as cone is formed by joining along the cuts. Side Length of the cut is radius of circle.
Remaining Area of the circle of 25cm radius becomes the lateral area of the cone.
R is radius of base circle of cone.
So 0.96 π 25² = π R L = π R 25
So R = 24 cm.
Height² = L² - R² This is because R L H form a pythagorus triangle.
Height = 7 cm
Ratio of radius to height is 24/7
when circular area of r =25cm is folded into a cone, the lateral length L of cone is = 25cm. as cone is formed by joining along the cuts. Side Length of the cut is radius of circle.
Remaining Area of the circle of 25cm radius becomes the lateral area of the cone.
R is radius of base circle of cone.
So 0.96 π 25² = π R L = π R 25
So R = 24 cm.
Height² = L² - R² This is because R L H form a pythagorus triangle.
Height = 7 cm
Ratio of radius to height is 24/7
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see diagram it will be easy.
thanx n u r welcom
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