25.

If the area of a circle is 100 cm2, find the

diameter.

The answer is 2 (√ (100) / √ (π)) cm.

Step-by-step explanation:

Since the area of a circle is π (r) ^2, you can write an algebraic equation to find the radius:

π (r) ^2 = 100

Simplify this by dividing both sides by π:

r^2 = 100/π

Then take the square root of both sides:

r = ± (√ (100) / √ (π))

Since radius can't be negative, the ± (plus-or-minus) becomes a plus.

r = √ (100) / √ (π)

Now, since the radius is half the diameter, you can write another algebraic expression:

2r=d

If you know algebra, you can solve solve the rest from here.

Plug in √ (100) / √ (π) for r:

2 (√ (100) / √ (π)) = d

Bam, you're done.

(not using the equation feature because I don't really know how yet. Will edit later)