Question

find the perimeter of a rectangle whose length is 40 centimetre and diagonal is 41 cm....by steps for 7th stander...
plz send fast
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Answer 1

Step-by-step explanation:

By Pythagoras theorem,

Diagonal ²=length ²+width ²

Now as given in the question,

Diagonal = 41 cm.

Length = 40 cm.

So, Putting these value we get,

41²=40²+width ²

width ²=41²-40²

width ²=1681-1600

width ²= 81

width=9

Hence the width of the rectangle is 9 cm.

So

The perimeter of the rectangle = 2 ( Length + Width )

= 2 ( 40 cm + 9 cm )

= 2 x 49 cm

= 98 cm

Hence the perimeter of the rectangle is 98 cm

Answer 2

Answer:

the perimeter of rectangle is 98 CM

Step-by-step explanation:

by by Pythagoras theorem

( Diagonal)^2 = ( Length)^2 + (Width)^2

now as given in question

diagonals = 41cm

length=40cm

so putting these value we get,

•(41)^2 =(40)^2+ (Width)^2

•(Width)^2 =(41)^2-(40)^2

•(Width)^2=1681-1600

•(Width)^2=81

• Width = 9cm

hence the width of rectangle is 9 CM

so

the perimeter of rectangle is 2 ( length + width)

= 2(40cm+9cm)

= 2*49cm

= 98 cm

hence the perimeter of rectangle is 98 CM