The figure shows a rectangular field DEFG. Warren walked from D to E to F to G and he covered a distance of 55 cm. Jean walked from E to F to G to D and she covered a distance of 44 cm.
- 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
Warren total covered distance
L + L + B = 55
2 L + B = 55 = A1
Jean total covered distance
B + L + B = 44
2 B + L = 44 = A2
A1 + A2
3 B + 3 L = 99
B + L = 99 ÷ 3 = 33 cm
Perimeter of the field
= 2 (B + L)
= 2 x 33
= 66 cm
(b)
Circumference of the semicircle
=
227 x 7 x
12 = 11 cm
Perimeter of the remaining field
= 66 + 11 - 7
= 70 cm
Answer(s): (a) 66 cm; (b) 70 cm