volume of cylinder = 3.14×1.5×1.5×4
1.34×2.25×4=
1.34×9=
12.06 in³
volume of cone =1/3×3.14×2×2×6
1/3×3.14×4×6
1/3×3.14×24
3.14×8
=25.12 in³
therefore he need to buy the cone shaped cup
