Question

a cone of height 28 cm has a surface area 2310 m2.the radius of the base is?​

Answer 1

Answer:

Let r cm be the radius and l cm the slant height. Then,

l²=r²+28²

l²=r²+784

l=√r²+784

​Curved surface area = 2310 cm²

πrl=2310

22/7​×r×√r2+784 =2310

​r√r2+784​=25×7

r²(r²+784)=25²×7²

$r^4$+784r²−(625×49)=0

(r²+625)(r²−49)=0

r=7

Volume = 1/3​πr²h

=1/3​×22/7​×49×24=1232 cm³