Math Papa is a very good calculator. You can try it. Just put the equation www.mathpapa.com :)
Like earlier take the bigger shape and divide the smaller one.
8.4 divide by 4 and you get 2.1.
The answer is probably like 8/11
The answer is False. Just googled it
The radius would be 40.82 divided 2 and that is 20.41 and the diameter would be 40.82 times 2 and that is 81.54
