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, l2+b2=d2

⟹402+b2=412

⟹b2=81

⟹b=9cm

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

Answer 2

Step-by-step explanation:

we have

length = 40 cm

Breadth = B

Diagonal = 41 cm

we know all angles of rectangle is equal to 90⁰

so in triangle ️ DBC

we will have

DC²= BC²+ÇD²

That is Pythagoras Theorm

we have

(41)²=(40)²+B²

B²= (41)²-(40²

B²=1618-1600

B²= 81

B= 9 cm

we have

area of rectangle = 2(40+9)

That is 98cm