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$$ \frac{2.5}{\sqrt{\pi}} $$ cm

Area of a Circle: Calculate The Missing Side based on the formula

Question 1

A circle has an area of 25 cm².

What is its radius?

Question 2

Look at the circle in the figure below.

What is the radius of the circle?

Question 3

Look at the circle in the figure.

What is the diameter of the circle?

A circle has an area of 25 cm².

What is its radius?

Area of the circle:

$S=\pi r^2$

We insert the known data:

$25=\pi r^2$

Divide by Pi: $\frac{25}{\pi}=r^2$

Extract the root: $\sqrt{\frac{25}{\pi}}=r$

$\frac{5}{\sqrt{\pi}}=r$

$\frac{5}{\sqrt{\pi}}$ cm

Look at the circle in the figure below.

What is the radius of the circle?

3 cm

Look at the circle in the figure.

What is the diameter of the circle?

14 cm