What is the radius and diameter of the following circle with 5.1

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label

Which of the choices shown could be used to prove that aacp=abcp ?

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base