Find the missing lengths of the sides.

B. a=3 in, b=3 √3 in

The short cuts for a 30 60 90 triangles is that the hypotenuse is twice as much as the short leg.

So to find the short leg you have to do
6/2 which is 3.

Another shortcut is that the long leg is that the long leg equals to short leg times √3.

So you have to do 3* √3 which equals to 3 √3