Answer:
![A=1347.7\ cm^2](https://tex.z-dn.net/?f=A%3D1347.7%5C%20cm%5E2)
Step-by-step explanation:
Given that,
Radius of a cone, r = 13 cm
Slant height of the cone, l = 20 cm
We need to find the surface area of the cone. The formula for the surface area of the cone is given by :
![A=\pi rl +\pi r^2](https://tex.z-dn.net/?f=A%3D%5Cpi%20rl%20%2B%5Cpi%20r%5E2)
Put all the values,
![A=\pi r(l + r)\\\\A=\pi \times 13(20 + 13)\\\\A=1347.7\ cm^2](https://tex.z-dn.net/?f=A%3D%5Cpi%20r%28l%20%2B%20r%29%5C%5C%5C%5CA%3D%5Cpi%20%5Ctimes%2013%2820%20%2B%2013%29%5C%5C%5C%5CA%3D1347.7%5C%20cm%5E2)
So, the surface area of the cone is
.
Answer: x is 20
Step-by-step explanation:
This is ratio
a : c = b : x and d : unknown
a : c = 9 : 12 = 3 : 4 which is 9/12
b : x = 15 : x which is 15 / x
So the proportion will be :
3/4 = 15/x
So Cross multiplying
3x = 90
Divide both side by 3
x = 90/3
x = 20
Here you go, hope this helps. If you need help with anything else feel free to reply to this comment
V = 30*16*12. To find the volume of a rectangular prism, you just multiply the area of the base (side 1 * side 2) by the height of the prism.