The figure shows a rectangular field KLMN. Justin walked from K to L to M to N and he covered a distance of 66 cm. Marion walked from L to M to N to K and she covered a distance of 48 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
Justin total covered distance
L + L + B = 66
2 L + B = 66 = A1
Marion total covered distance
B + L + B = 48
2 B + L = 48 = A2
A1 + A2
3 B + 3 L = 114
B + L = 114 ÷ 3 = 38 cm
Perimeter of the field
= 2 (B + L)
= 2 x 38
= 76 cm
(b)
Circumference of the semicircle
=
227 x 7 x
12 = 11 cm
Perimeter of the remaining field
= 76 + 11 - 7
= 80 cm
Answer(s): (a) 76 cm; (b) 80 cm