Answer:
b = (13 root under 3)/2
Explanation:
taking 60 as reference angle,
cos60 = b/h
1/2 = x/15
or, 15 = 2x
so, x = 7.5
Now
h² = p² + b²
15² = x²+z²
225 = (7.5)²+z²
or, 225-56.25 = z²
or, z² = 168.25
so, z = 12.97
so, z = 13 approximately
now
sin60 = p/h
or, sin60 = y/x
or, sin60 = y/7.5
or, sin60.7.5 = y
so, y = 6.5
now
taking 30 as reference angle,
cos30 = b/h
or, cos30 = b/z
or, cos30 = b/13
or, cos30.13 = b
so, b = 11.3 approximately