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The height of a cone is 8m and its Curved Surface Area is 188.4m².Find its volume.(Take π=3.14) |
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Answer» Correct question:- The height of a CONE is 8m and its CURVED surface AREA is 188.4m².FIND its volume (Take π = 3.14) Given:-→Height of the cone=8m →C.S.A of the cone=188.4m² →Value of π= 3.14 To find:-→Volume of the cone Solution:-Let the radius be r metre and the slant height be l metres. =>C.S.A of a cone= πrl m² => πr√r²+h² m² =>(3.14×r×√r²+64)m² =>3.14×r×√r²+64=188.4 =>r√r²+64 = 188.4/3.14 =>r√r²+64 = 60 =>r²(r²+64) = 3600 =>r²+64r²-3600 = 0 =>(r²+100)(r²-36)=0 Since,r²= -100 gives an imaginary value of r =>r²=36 =>r=6 Hence,we got radius of base of the cone as 6m. =>Volume of a cone= 1/3πr²h =>1/3×3.14×6×6×8 =>904.32/3 =>301.44 m³ Thus,volume of the cone is 301.44m³. |
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