core: 2)
2. The sides of a rectangle are in the ratio 2:3
a) If the breadth is 2a, what is the length?
b) If the perimeter of the rectangle is 40cm, find the length and breadth?
Answers
Answer:
a) Let the sides of the rectangle be 2x and 3x
then,
A.T.Q-
breadth=2x=2a
x=a
then,3x=3a
b)given-
perimeter of the rectangle=40cm
now,
according to above solution ,sides of rectangle=
3a and 2a
then,
3a+2a=40
5a=40
a=8
sides-
length=3a=24cm
breadth=2a=16cm
Given:
The ratio of the sides of the rectangle = 2:3
The perimeter of the rectangle = 40 cm
To Find:
The length and breadth of the rectangle.
Solution:
The assumption, the breadth of the rectangle = 2a
The perimeter of the rectangle = 2×( length + breadth)
⇒ The perimeter of the rectangle = 40 cm
⇒ 2 × (length + breadth) = 40 cm
⇒ (Length + Breadth) = 20 cm
And the ratio of breadth to the length = 2:3
⇒ length/ breadth = 2/3
⇒ Length = (3/2) × 2a = 3a
Replacing values of the length and the breadth
⇒ perimeter = [2{2a + (3a)}] = 10a = 40 cm
⇒ a = 4 cm
The length of the rectangle = 3a = 12 cm
The breadth of the rectangle = 2a = 8 cm
Hence, the length and breadth of the rectangle are 12cm and 8cm, respectively.