Calvin is using the formula A=3r^2 to estimate the area of a circle.

Solve for r

Use your equation to estimate the radius of a circle with an approximate area of 300 cm^2

3r^2 = 300

r^2 = 100
now finish it off

10

To solve for r in the equation A = 3r^2, we need to isolate r.

Step 1: Start with the equation A = 3r^2.

Step 2: Divide both sides of the equation by 3 to get A/3 = r^2.

Step 3: Take the square root of both sides to find r. So, √(A/3) = r.

Now, let's use this equation to estimate the radius of a circle with an approximate area of 300 cm^2.

Step 4: Substitute A = 300 cm^2 into the equation √(A/3) = r.

Step 5: Simplify the equation: √(300/3) = r.

Step 6: Perform the calculations: √100 = r.

Step 7: Simplify the square root: 10 = r.

Therefore, the estimated radius of a circle with an approximate area of 300 cm^2 is 10 cm.

To solve for r in the formula A=3r^2, we need to isolate r on one side of the equation.

Let's start by dividing both sides of the equation by 3:

A/3 = r^2

Next, we want to eliminate the square root of r^2, so we take the square root of both sides of the equation:

√(A/3) = r

Now, we have solved for r in terms of A. So, to estimate the radius of a circle with an approximate area of 300 cm^2, we can plug this value into the formula.

r = √(300/3)
r = √100
r = 10 cm

Therefore, the estimated radius of the circle is 10 cm.