Tiffany makes a round pizza. She wants to put a cheese layer on the pizza. If the pizza has a diameter of 18 cm, how many square cm of cheese layer does she need to put on the pizza?

Step-by-step explanation:

Given that,

The diameter of the pizza, d = 18 cm

We need to find the square cm of cheese layer does she need to put on the pizza.

We know that the area of the circle is given by :

Where

r is the radius of the circle

Here, r = 9 cm

So,

So, the area of the pizza is .

step-by-step explanation:

we are given

since, we have to isolate x on anyone side

so, we can move all x terms on one side

subtract both sides by 2x

add both sides by 9

divide both sides by 4

we get