Question

the area pf a circle is increased by 22 sq cm when its radius is increased by 1 cm. The original radius of the circle is what?​

Answer 1

check the Attachment

Answer 2

Answer

3 cm

Here is the attachment

By the way , I am terribly sorry for that horrible handwriting

Here is a small explanation

Now the hardest step is the part where we subtract

$\pi {(r + 1)}^{2} and \: \pi {r}^{2}$

Now , in the question it is given that with one centimetre increase the radius, there is 22cm² increase in the area.

Going with this information, we can see that the final area minus the initial area is 22 centimetres²

now the final area is

.

$\pi {(r + 1)}^{2}$

And the initial area is

$\pi {r}^{2}$

And ..... that was the hardest part . if anyone has any doubts about this ,just comment and I'll answer it (or someone else from this amazing platform )

Hope you had a nice day