Question

a circular park of 28m diameter has been constructed. A 3.5m circular track outside has been developed along the park. using algebraic formula, find the area of the track around the park

Answer 1

The diameter(d) of the circular park is 28m.
So, the radius of the park is:
r = d/2
r = 28/2 = 14m

The width of the track developed outside the area of the park is 3.5m
So lets consider R to be the radius of the bigger circle formed by the park + the circular track.
R = r + width of track
R = 14 + 3.5
R = 17.5m

Area of the track = Area of the bigger circle formed by park and track - Area of the park
Area of track = π R² - π r² = π (R² - r²)
Area of track = 22/7 (17.5² - 14²)
Area of track = 346.5 m²