The figure shows a rectangular field ABCD. Flynn walked from A to B to C to D and he covered a distance of 69 m. Elyse walked from B to C to D to A and she covered a distance of 39 m.
- What is the perimeter of the field?
- Some construction work was undertaken to the same field and a semi-circular part was removed from it. What Is the perimeter of the field after the construction? (Take π = 227)
(a)
Lets assume Length → L and Breadth → B
Flynn total covered distance
L + L + B = 69
2 L + B = 69 = A1
Elyse total covered distance
B + L + B = 39
2 B + L = 39 = A2
A1 + A2
3 B + 3 L = 108
B + L = 108 ÷ 3 = 36 m
Perimeter of the field
= 2 (B + L)
= 2 x 36
= 72 m
(b)
Circumference of the semicircle
=
227 x 7 x
12 = 11 m
Perimeter of the remaining field
= 72 + 11 - 7
= 76 m
Answer(s): (a) 72 m; (b) 76 m