How to find the area of the incircle of a triangle (shortcut first, then proof)
8:47
You use the inscribed angle theorem all the time, but why is it true?
6:38
Finding the area of the circumcircle of a triangle
8:31
Raiz quadrada de um número imaginário
9:50
How to really solve sin(x^2)=sin(x)
21:40
Same perimeter, different areas: Which is the largest? The Isoperimetric Problem
19:14
The strange cousin of the complex numbers -- the dual numbers.
28:37
final de xadrez 300
48:59