Question

what is the perimeter of a circle if it has the radius of 8.1 cm​

Answer 1

Heya mate... here you go with the answer...

Circumference of a cicle in terms of radius:

Circumference = 2·π·r = 2·3.14·8.1 = 50.89(*)

In terms of diameter:

Circumference = π·d = 3.14·16.2 = 50.87(*)

In terms of area:

Circumference C = √4·π·A = √4·π·206.1 = 50.89(*)

(*) 50.89 cm exactly or limited to de precision of this calculator (13 decimal places).

Note: for simplicity, the operations above were rounded to 2 decimal places and π was rounded to 3.14.

have a good day ahead...