Length of an Arc = θ × r, where θ is in radian. Length of an Arc = θ × (π/180) × r, where θ is in degree.
we should get r from the circle area
circle area = pi r²
20 = 3.14 * r²
r² = 6.37
r = 2.5
Arc length = θ × r
4.5 = θ * 2.5
θ = 1.8 this answer in radian
to convert to degree
θ* 180/π
= 1.8 * 180/π
= 103.132 degrees
