The formula of a surface area of a cone:
[tex]S.A.=\pi r^2+\pi rl[/tex]
r - radius
l - slant height
We have r = 7cm and l = 10cm. Substitute:
[tex]S.A.=\pi(7^2)+\pi(7)(10)=49\pi+70\pi=119\pi[/tex]
