Question

find the TSA of cone if slant hight is 21m and diameter of base is 24 meter

Answer 1

slant height(l) =24m         diameter=24m
                                            radius= 24/2=12m
Total Surface Area of Cone = $\pi$r[r+l]
                                             = $\pi$*12[12+24]
                                             =22/7 *12*36
                                             =1357.7  m^{2} 

Answer 2

since diameter=24m
so,radius=12m
slant height=21m
so,T.S.A=Pi×r×l(l+r)
=22/7×12×21(21+12)
=264/7×21(21+12)
=(792×33)m^2
=26136m^2