Question

The area of a rectangle of length 21cm and diagonal 29cm is _______

a) 609 cm2

b) 580 cm2

c) 420 cm2​

Answer 1

Answer:

${420cm}^{2}$

Step-by-step explanation:

Length = 21 cm Diagonal = 29 cm

By the converse of Pythagoras theorem, AB2 + BC2 = AC2 212 + x2 = 292 x2 = 841 – 441 = 400 = 202 x = 20 cm.

Now area of the rectangle = length x breadth. i.e. AB x BC = 21 cm x 20 cm = 420 cm2

Answer 2

Answer:

The correct option is ( C ) - 420cm²