Question

The diameter of a circle is 9 cm. Find its area to the nearest tenth.

Answer 1

63.6

Explanation:

1. A = πr²

2. Find the radius (r). Since the radius of a circle is the diameter/2, the radius is 9/2, which is 4.5

3. Now that we know the radius, we plug it into our formula: A = π(4.5)²

4. Simplify: A = 3.14(20.25)

5. A = 63.62

6. Rounding to the nearest tenth makes your answer 63.6

Answer 2

63.6 cm

Cut diameter in half to find radius

9/2 = 4.5

radius = 4.5

This is the formula for area of a circle:

pi * radius^2

pi * 4.5^2

20.25pi

Now find pi:

20.25 * pi = 63.6

Answer:

63.6 cm is the area