Answer:
L = 245 cm2 ; S = 358.1 cm2
Explanation:
The lateral area of a right cone with radius r and slant height l is L=πrl.
The figure shows a right cone.
Apply the formula for the lateral area of a right cone L=πrl.
Substitute the known values for the radius r=6 cm and the slant height l=13 cm.
L=π(6)(13)=78π
Use a calculator to approximate. Round your answer to the nearest whole number.
L≈245
The lateral area of the cone is 245 cm2.
The surface area of a right cone with lateral area L and base area B is S=L+B, or S=πrl+πr2.
Substitute the given value for the radius r=6 cm into the formula for the area of a circle, B=πr2.
B=π(6)2=36π
Therefore, the base area is 36π cm2.
To calculate the surface area of the cone, substitute the known values into formula for surface area.
S=78π+36π=114π
Use a calculator to approximate. Round your answer to the nearest tenth.
S≈358.1
Therefore, the surface area of the cone is about 358.1 cm2.