Someone ! , i don't understand it : ( !

To find the volume of a cylindrical object, you have to multiply the radius² by height by .

Since the question only asks about the volume of just the juice, and says that the glass is 3/4 full, you would take 3/4 of 8 centimeters, which would be 6 centimeters.
Now you would find the radius, which is half of the diameter. Meaning that 6 divided by 2 would be 3, making your radius 3 centimeters.
Now 3² is 9. 9·6 would be 54.
Your answer would be 54 cm³.