Question

Find the perimeter of the rectangle whose length is 40 cm and a diagonal is 41 cm.

Answer 1

Given diagonal (PR) = 41 cm, length (PQ) = 40 cm Let breadth (QR) be x cm. Now, in right angled triangle PQR, 

Therefore the breadth of the rectangle is 9 cm. 

Perimeter of rectangle = 2(length + breadth) 

= 2 (9 + 40) = 2 x 49 = 98 cm 

Hence the perimeter of the rectangle is 98 cm.