Solution:
As, You have Written Polygon ABCD is a rectangle.
It is a Four sided Polygon , having all it's interior angles equal to 90°.As well as Opposite sides are equal(AB=CD,AD=BC), equal diagonals(AC=B D).
Join any of the diagonal of Rectangle either AC or B D.
In Right Δ ABC , Right angled at B
---(1)
In Right Δ ADC , Right angled at D
---(2)
Adding (1) and (2) that is LHS to LHS and RHS to RHS
Ar( Δ ABC) +Ar( Δ ADC)
So, Area of Rectangle= Product of any two Adjacent Sides
