Question

the diagonal of a rectangle is 25 inches . the width is 15 inches. what is its length?

Answer 1

Heya user .
Here is your answer !!

_____________

Diagonal of the rectangle = 25 inches .
Breadth of the rectangle = 15 inches .
Length of the rectangle = ?

Now , we know that ,
√ ( l² + b² ) = d.
=> l² + b² = d² [ Squaring both sides ] .
=> l² = d² - b²
=> l = √ ( d² - b² )
=> l = √ ( 25² - 15² )
=> l = √ 20²
=> l = 20

So , the length if the rectangle is 20 inches .

_____________

Hope it helps !!

Answer 2

let the length of the rectangle is x inches
so the diagonal and each of its length and breadth form a right angled triangle
so in a rectangle,
diagonal ^2 = length^2+breadth^2
or 25^2=x^2+15^2
ie x^2=625-225=400
or x= 20
so length is 20 inches