Usually the easiest way to solve this is by using a calculator. Of course only if your teacher allows you too.
Step-by-step explanation:
8(b+1)=-3(2+b)
8b+8=-6-3b
8b +3b = -6-8
11b = -14
b = -14/11
It appears that the Pythagorean theorem can be applied to this problem
(distance to shadow)² = (height of building)² + (length of shadow)²
(38 m)² = (height of building)² + (28 m)²
660 m² = (height of building)²
Then the height of the building is
height of building = √660 m ≈ 25.7 m
Arctan (√3 /3) = 30°. = π/6 rad
That is the value searched, in degrees and radians.
You can verifiy that tan(30°) = sin(30°) / cos(30°) = [1/2] / [√3/2] = 1/√3 = √3 / 3
