Area of a Circle

Front

What is the formula for the area of a circle?

Back

A = π·r², where A is the area and r is the radius.

Front

What does π (pi) represent in the area formula?

Back

π is a mathematical constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.

Front

If the radius of a circle is 3 cm, what is its area?

Back

A = π·(3)² = 28.26 cm².

Front

What is the radius of a circle with an area of 50.24 cm²?

Back

r = √(A/π) = √(50.24/π) ≈ 4 cm.

Front

What does 'r' represent in the formula A = π·r²?

Back

r represents the radius of the circle.

Front

How do you find the area of a circle if you know the diameter?

Back

First, divide the diameter by 2 to get the radius, then use the formula A = π·r².

Front

What is the area of a circle with a radius of 5 cm?

Back

A = π·(5)² = 78.54 cm².

Front

If the area of a circle is 78.54 cm², what is the radius?

Back

r = √(A/π) = √(78.54/π) ≈ 5 cm.

Front

What is the relationship between the diameter and radius of a circle?

Back

The diameter is twice the radius (d = 2r).

Front

What is the area of a circle with a radius of 10 cm?

Back

A = π·(10)² = 314.16 cm².