If the area of a circle is 154 cm², what is the radius of the circle? (Use π = 2

If the area of a circle is 154 cm², what is the radius of the circle? (Use π = 22/7)

If the area of a circle is 154 cm², what is the radius of the circle? (Use π = 22/7)

Step 1: Write down the formula for the area of a circle, which is Area = πr².
Step 2: Substitute the given area (154 cm²) and the value of π (22/7) into the formula: 154 = (22/7)r².
Step 3: To eliminate the fraction, multiply both sides of the equation by 7: 154 * 7 = 22r².
Step 4: Calculate 154 * 7, which equals 1078. Now the equation is 1078 = 22r².
Step 5: Divide both sides by 22 to solve for r²: r² = 1078 / 22.
Step 6: Calculate 1078 / 22, which equals 49. Now we have r² = 49.
Step 7: To find the radius (r), take the square root of 49: r = √49.
Step 8: Calculate the square root of 49, which is 7. Therefore, the radius of the circle is 7 cm.

Area of a Circle – The area of a circle is calculated using the formula A = πr², where A is the area and r is the radius.
Substitution and Rearrangement – The question tests the ability to substitute known values into a formula and rearrange it to solve for an unknown variable.
Use of Approximation for π – The question requires the use of a specific approximation for π (22/7) instead of the more common 3.14.