Question

diagonal of rectangle=15cm
length=12cm
area=?​

Answer 1

Answer:

Given that,

Digonal of a rectangle is 15cm

Width =12cm

We know that,

d=

w

2

+l

2

l=

d

2

−w

2

d=

15

2

+12

2

l=

15

2

−12

2

=

225−144

=

81

=9

Then,

We get the length of the rectangle is 9cm.

Answered By

toppr

Answer 2

Answer:

suppose ABCD is any rectangle.

diagonal of rectangle = BD = 15 cm

length = AB = 12cm

breadth = AD = ?

area = ?

in ∆ ABD, <BAD = 90°

by Pythagoras theorem,

(BD)^2 = (AB)^2 + (AD)^2

(15)^2= (12)^2 + (AD)^2

225 = 144 + (AD)^2

225-144 = (AD)^2

81 = (AD)^2

taking square root,

AD = √81

AD= 9 cm

now,

area of rectangle ABCD = length x breadth

= 12 × 9

= 108 cm^2