Answer:
[tex]13194.7\ mm^2[/tex]
Step-by-step explanation:
The total surface area of a cone is given by:
Surface area = [tex]\pi r(r+\sqrt{h^2+r^2} )[/tex]
where r is the radius of the cone, h is the height of the cone, l is the length of the cone = [tex]\sqrt{h^2+r^2}[/tex]
Given that h = 136 mm, r = 60 mm /2 = 30 mm, l = 140 mm. Also the top of the cone is not included in the surface area, hence the surface area becomes:
[tex]Surface \ area=\pi r(\sqrt{h^2+r^2} )=\pi rl\\\\Surface \ area=\pi (30\ mm)(140\ mm)=13194.7\ mm^2[/tex]