Question

Hello i am new to chemistry and i have a problem on how to use this formula. Can anyone help me?

Calculate the volume of the 50mL graduated cylinder using your measurements of diameter and height, using the formula V = ∏ r2h (r=½ diameter). This is your experimental value. Assuming the accepted value of the volume of the graduated cylinder is 50.00 mL, calculate the percent error of your volume calculation, using the following formula:
Percent Error = /accepted value -My professor us asking me to acquire the volume of a 50 mL graduated cylinder.