Khan Academy on a Stick
45-45-90 Triangle Side Ratios
Showing the ratios of the sides of a 45-45-90 triangle are 1:1:sqrt(2)
If the above player doesn't work, you can try this direct link.
Showing the ratios of the sides of a 45-45-90 triangle are 1:1:sqrt(2)
If the above player doesn't work, you can try this direct link.