Answer:
The diameter = 0.56 m ( or 56 cm).
Step-by-step explanation:
Let the diameter = D cm.
The total length of a semicircle
= diameter + length of the half circle
= D + π * radius
The radius = D/2, so
Total length = D + π * D/2
The total length is 144, so:
D + π * D/2 = 144
Taking π = 22/7
D + 22D/(2*7) = 144
Multiplying each term by 14:
14D + 22D = 2016
D = 2016 / (14 + 22)
= 2016 / 36
= 56 cm .