Question

The surface area of a cone with radius r units and slant height s units is shown below:

Surface area = 3.14(rs + r2)
Part A: If r = 2 units and s = 3 units, write an expression that can be used to calculate the surface area of the cone.

Part B: What is the surface area of the cone? Show your work.

Answer 1

Answer:

314 unit ^2

Step-by-step explanation:

Part A

The expression that can be used to calculate surface area is

$\pi \: r \: (l \: + r)$

Part B

Surface area = 3.14 × 2 (2+3)

= 3.14 × 10 = 314 unit ^2

Answer 2

Given:

The surface area of a cone with radius r units and slant height s units is given by  

 $3.14(rs+r^2)$.

To Find:

(a) Expression that can be used to calculate the surface area of the cone?

(b) Surface area of the cone?

Step-by-step explanation:

• An expression that is used to calculate the surface area of a cone is    $\pi r(l+r)$ .

        where r is the base radius of a cone and l is the slant height

        of cone.

• The slant height of a cone is calculated by the following formula.

         $l=\sqrt{r^2+h^2}$

         where r is the base radius of the cone and h is the height of

         the cone.

• The surface area of the cone when the radius is 2 units and

         slant height is 3  units.

         The surface area of a cone $=\pi r(l+r)$

                                                       $=3.14\times2(3+2)\\=3.14\times10\\=31.4unit^2$

The surface area of the cone is $31.4 units^2$.