In order to minimize the given expression, we can maximize h right? And the angle opposite to greater side will be greater.

Keep in mind that b ≥h

Oh yeah! My bad. Didn’t read that. But then how do we solve this?

If the angel b/w t and b is 30 then the above fraction is greater than when the angel was 45. (so, value of the fraction will increase if the value of the angle b/w t and b is decreased -->Hence, all the values below and including 30 are out )

Now, we can’t check for other values because if we make angel b/w t and b = 60 then h> b and that violates the constraint given (b ≥ h)