Question

Diagonals of rectangle are

Answer 1

The number of diagonals in a polygon = n(n-3)/2, where n is the number of polygon sides. 
Therefore, number of diagonals in rectangle = 4(4 -1)/2 = 4*1/2 = 2

Answer 2

Answer:

A rectangle has two diagonals, which are line segments linking opposite vertices (corners) of the rectangle.

A diagonal of a rectangle divides it into two right triangles. The diagonal of the rectangle is the hypotenuse of these two triangles. We can use Pythagoras' Theorem to find the length of the diagonal if we know the width and height of the rectangle.

Diagonal =  √   w^2  +  h^2    

where:

w  is the width of the rectangle

h  is the height of the rectangle