Is it possible to design a rectangular park of perimeter 80 and area 400 sq.m.? If so find its length and breadth.
Answers
➥ Let the length be ℓ m and Breadth be b m.
⇛Then the area will be l × b = 400m²
⇛Perimeter will be 2(l + b) = 80m
→ l × b = 400
→ 2(l + b) = 80
→ l + b = 40
→ b = 40 - l (i)
Substituting (1) in Area, we get;
→ l(40 - l) = 400
→ 40l - l² = 400
→ l² - 40l + 400 = 0
→ (l - 20)(l - 20) = 0
→ l = 20m
→ b = 40 - 20 = 20m
✓ We now know that the length of the park is 20 m and the breadth of the park is also 20 m.
Hope this helps uh! :)
Is it possible to design a rectangular park of perimeter 80 and area 400 sq.m.? If so find its length and breadth.
Let the length be l m and the breadth be b m.
Then the area would be lb=400
Perimeter would be 2(l+b)=80
lb=400
⇒2(l+b)=80
⇒l+b=40
∴b=40−l --(1)
Substituting (1) in Area, we get
⇒l(40−l)=400
⇒40l−l2=400
⇒l2−40l+400=0
⇒(l−20)(l−20)=0
∴l=20
has equal roots, so it is possible to design the rectangle of given parameters.
⇒b=40−20=20
- I Hope It's Helpful My Friend Ayan.