For a 30-60-90 right triangle the legs will be 2 and 2sqrt(3), so that the area would be 1/2 * 2 * 2sqrt(3) = 2sqrt(3) = 3.46
For a 45-45-90 right triangle the legs will be 2sqrt(2) and 2sqrt(2) so that the area would be 1/2 * 2sqrt(2) * 2 sqrt(2) = 4