Volume and surface area
15:51
But why is a sphere's surface area four times its shadow?
5:02
Trick for doing trigonometry mentally!
16:23
Total Surface Area - the trick to getting it right
5:27
Surface Area to Volume Ratio
21:40
Same perimeter, different areas: Which is the largest? The Isoperimetric Problem
28:43
The ALMOST Platonic Solids
5:39
9 Awesome Science Tricks Using Static Electricity!
4:37