we know that surface area of the cone (SA)=pi*r²+pi*r*l where r is the radius l is the slant height SA=306*pi cm² diameter=12 cm r=12/2----> r=6 cm SA=pi*r²+pi*r*l--------> [SA-pi*r²]=pi*r*l----> l=[SA-pi*r²]/[pi*r] l=[306*pi-pi*6²]/[pi*6]---> [306*pi-36*pi]/[6*pi]---> 45 cm
the answer is the length of the slant height is 45 cm
