Question

I WILL GIVE 20 POINTS TO THOSE WHO ANSWER THIS QUESTION RIGHT NOOOO SCAMS AND EXPLAIN WHY THAT IS THE ANSWER

Answer 1

Answer:

$A = 297\pi$

Step-by-step explanation:

To solve this problem we need to be familiar with the formula for the surface area of a cone:

$A = \pi r(r + \sqrt{h^2+r^2})$

We are given the length of a side and the diameter, to calculate the radius divide the diameter in half:

$r = \frac{d}{2}\\r = \frac{18}{2}\\r = 9 cm$

To calculate the height of the cone, we must use the Pythagorean Theorem:

$C^2 = A^2 + B^2$

We can treat the side length as the hypotenuse $C$, the radius as the base $A$, and solve for height $B$. Set the expression up like this:

$C^2 = A^2 + B^2\\24^2 = 9^2 + B^2\\B^2 = 24^2 - 9^2\\B = \sqrt{24^2 - 9^2}\\B = \sqrt{576 - 81}\\B = \sqrt{495}\\B \approx 22.25$

Now we can plug into our original formula:

$A = \pi r(r + \sqrt{h^2+r^2})\\A = \pi 9(9+\sqrt{\sqrt{495}^2+9^2}\\A = \pi 9(9+\sqrt{495 + 81}\\A = \pi 9(9+\sqrt{576})\\A = \pi 9(9 + 24)\\A = \pi 9(33)\\A = 297\pi$