Question

The diagonal of rectangle is 50 cm, its breadth is 30 cm then the perimeter is
(A) 70 cm
(B) 160 cm
(C) 140 cm
(D) 90 cm​

Answer 1

Answer:

160

by PGT find length and then multiply it with 4

Answer 2

Answer:

(c) 140 cm

Step-by-step explanation:

Given :

Diagonal of a rectangle = 50 cm.

Breadth of the rectangle = 30 cm.

Formulae :

Diagonal of a rectangle = $\sqrt{l^{2} + b^{2}}$ units [Pythagoras Theorem]

Perimeter of a rectangle = 2(l + b) units

Procedure :

⇒ 50 cm = $\sqrt{l^{2} + b^{2}}$

Squaring on both sides,

⇒ 2500 cm² = l² + b²

⇒ 2500 cm² = l² + (30 cm)²

⇒ l² = 2500 cm² - 900 cm²

⇒ l² = 1600 cm²

⇒ l = ± 40 cm.

As length can never be negative,

∴ l = 40 cm.

As l = 40 cm and b = 30 cm,

Perimeter of the rectangle = 2(l + b) units

⇒ P = 2(40 + 30) cm

⇒ P = (2 × 70) cm

∴ P = 140 cm

Hence the perimeter of the Rectangle = 140 cm.

Hence option(c) is the correct answer.

Thanks !