Question

find the perimeter of the rectangle whose length is 40 cm and a diagonal is 41 cm​

Answer 1

Answer:

Given that length of the side of the rectangle is l=40cm and

the length of the diagonal is d=41cm

let breadth be bcm

Therefore, l

2

+b

2

=d

2

⟹40

2

+b

2

=41

2

⟹b

2

=81

⟹b=9cm

we know that the perimeter of the rectangle is 2(l+b)=2(40+9)=98cm

Answer 2

Answer:

PERIMETER IS 98CM

Step-by-step explanation:

length,l=40 cm. Breadth=b

diagonal,d²=l²+b²

b=√(d²-l²)

perimeter=2l +2b

=2l +2√(d²-l²)

=2*40+2√(41²-40²)

=80+2√(41-40)(41+40). { a²-b²=(a+b)(a-b)}

=80+2*√81

=80+2*9

=80+18

=98 cm