Question

NO LINKS!!! URGENT HELP PLEASE!!!​

Answer 1

8) 162.11 in²

9) 499.20 km²

Explanation:

We need to find the surface area of the cones given their base diameter and slant height.

The formula for the surface area of a cone is:

`\boxed{S.A.=\pi r(r+s)}`

where:

• r is the radius of the circular base.
• s is the slant height.

`\hrulefill`

Question 8

The diameter of a circle is twice its radius.

Given the diameter of the circular base is 8 in, its radius is r = 4 in.

Therefore:

• r = 4 in
• s = 8.9 in

To calculate the surface area of the cone, substitute these values into the formula:

`\begin{aligned}\textsf{Surface area}&=4\pi (4+8.9)\\&=4\pi(12.9)\\&=51.6\pi\\&=162.1061809...\\&=162.11\; \sf in^2\end{aligned}`

Therefore, the surface area of the cone is 162.11 in², rounded to the nearest hundredth.

`\hrulefill`

Question 9

The diameter of a circle is twice its radius.

Given the diameter of the circular base is 14 km, its radius is r = 7 km.

Therefore:

• r = 7 km
• s = 15.7 km

To calculate the surface area of the cone, substitute these values into the formula:

`\begin{aligned}\textsf{Surface area}&=7\pi (7+15.7)\\&=7\pi(22.7)\\&=158.9\pi\\&=499.1990726...\\&=499.20\; \sf km^2\end{aligned}`

Therefore, the surface area of the cone is 499.20 km², rounded to the nearest hundredth.

Answer 2

8. 162.11 in²

9. 499.2 km²

Explanation:

Total Surface Area or TSA of cone = πr(r + l)

where r is radius and l is slanted height.

For question 8.

diameter=8in

radius(r)=diameter/2=8/2=4

slanted height(l)=8.9 in

Now

substituting value of r and l in formula:

Total Surface Area of cone = π*4(4+8.9)=162.11 in²

For question 9.

diameter=14 km

radius(r)=diameter/2=14/2=7

slanted height(l)=15.7 in

Now

substituting value of r and l in formula:

Total Surface Area of cone = π*7(7+15.7)=499.20 km²