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Question
Find the curved surface area , the total surface area and the volume of a cone if its :
Height = 15 cm , radius = 8 cm
Solution
Height = 15 cm , radius = 8 cm
Curved surface area = `(pir sqrt(h^2 + r^2))`
= `22/7 xx 8 xx sqrt(15^2 + 8^2)`
= `22/7 xx 8 xx sqrt(289)`
= `22/7 xx 8 xx 17`
= 427.43
Curved surface area = 427.43 cm2
Total surface area = area of circular base + curved surface area
= `pir^2 + (pir sqrt(h^2 + r^2))`
= `22/7 xx 8 xx 8 + 427.43`
= `201.14 + 427.43`
= 628.57
Total surface area = 628.57 cm2
Volume = `1/3 xx (pir^2) xx h`
= `1/3 xx 22/7 xx 8 xx 8 xx 15`
= 1005.71
Volume of the cone = 1005.71 cm3
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