Solve the following question:

In any right angled triangle , if one of the angles squeezes to 0 then the length of the perpendicular becomes 0 and we know that sinA = P/H , Now for A = 0 , P=0 , sin0 = 0

Similarly if any angle other that the right angle is 90 then base becomes 0 , hence cos90 = B/H = 0

When one angle is 45 then the triangle become right angled iscoceles triangle , so P = B , hence tan45 = P/B = 1 .