To solve for \( d \) in the equation \( A = \frac{\pi d^2}{4} \), we need to isolate \( d \). First, multiply both sides by 4 to eliminate the fraction, then divide by \(\pi\) to isolate \( d^2 \). Finally, take the square root of both sides to solve for \( d \).
Step 1: Rearrange the Equation
Start with the equation for the area of a circle in terms of diameter:
\[ A = \frac{\pi d^2}{4} \]
Step 2: Eliminate the Fraction
Multiply both sides by 4 to eliminate the fraction:
\[ 4A = \pi d^2 \]
Step 3: Isolate \( d^2 \)
Divide both sides by \(\pi\) to solve for \( d^2 \):
\[ d^2 = \frac{4A}{\pi} \]
Step 4: Solve for \( d \)
Take the square root of both sides to solve for \( d \):
\[ d = \sqrt{\frac{4A}{\pi}} \]
Step 5: Substitute the Given Value
Substitute \( A = 10 \) into the equation:
\[ d = \sqrt{\frac{4 \times 10}{\pi}} \]
Step 6: Calculate the Value
Calculate the value of \( d \):
\[ d \approx 3.568 \]