If the two triangles are congruent it means that their side lengths are equal, so we can assume that x = 3x - 8 and so 2x = 8 and x = 4. Hope that helps :)
From the trigonometry:
tan θ = (sin θ) / (cos θ)
cot θ = (cos θ) / (sin θ)
∴ tan θ + cot θ = (sin θ) / (cos θ) + (cos θ) / (sin θ)
= [ sin² θ + cos² θ]/( sin θ cos θ) = 1 /( sin θ cos θ )
note : sin² θ + cos² θ = 1
Forty-thousand, five-hundred eighty-three.
Circumference = πd = 3.14*559 = 1755.26
The spokes divide the circumference into 32 arcs. Each arc length is 1755.26/32 = 54.75 mm