7.5
You can work out the radius firstly.
multiply or divide
If you have the radius, then area = pi*r2 which you then round to the nearest hundredth. If you do not know the radius but do know the diameter or circumference, you can calculate the radius. Otherwise you need to measure it.
30.46 but round it to the nearest decimal and it will be 30.50
47.25
3 hight
10.4 cm
509 cm
A circle with a radius of 4 units has a circumference of 25.13 units.
Area = pi*r2 = 3217 sq inches to the nearest integer.
3.8
It is: pi*15.42 = 745.06 square units