Question

What is the largest area of a circle that can be made from a piece of thread 25.2cm long assume no knot

Answer 1

Answer:

$50.2 cm^2$

Explanation:

Here we want to find the largest area of a circle that can be made from a piece of thread 25.2 cm long, assume no knot .

This means that the circumference of the circle must equal to the length of the thread, so we can write:

L = 25.2 cm

And the circumference can be written as:

$2\pi r = L = 25.2$

where

r is the radius of the circle

Solving for r, we find the radius:

$r=\frac{L}{2\pi}=\frac{25.2}{2\pi}=4.0 cm$

The area of a circle is given by the formula

$A=\pi r^2$

So in this case, we find:

$A=\pi (4.0)^2=50.2 cm^2$