The figure shows a rectangular field DEFG. Cody walked from D to E to F to G and he covered a distance of 75 m. Shiyun walked from E to F to G to D and she covered a distance of 51 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
Cody total covered distance
L + L + B = 75
2 L + B = 75 = A1
Shiyun total covered distance
B + L + B = 51
2 B + L = 51 = A2
A1 + A2
3 B + 3 L = 126
B + L = 126 ÷ 3 = 42 m
Perimeter of the field
= 2 (B + L)
= 2 x 42
= 84 m
(b)
Circumference of the semicircle
=
227 x 7 x
12 = 11 m
Perimeter of the remaining field
= 84 + 11 - 7
= 88 m
Answer(s): (a) 84 m; (b) 88 m