AB=30m BC=15m CD=30m AD=15m

as opposite  sides are equal, therefore, it is a rectangle.

diagonal BD divides it into two equal parts.

now, in ΔABD, let AB=30m=base

                        let AD=15m=height

thus, area ΔABD= 1/2 × base × height

                           = 1/2 × 30 × 15 m²

                           = 15 × 15 m²

         area ΔABD= 225 m²

similarly, in ΔBCD, let DC=30m=base

                               let BC=15m=height

thus, area ΔBCD=area ΔABD=225m²

now, area quad. ABCD= area ΔABD + area ΔBCD

                                     = 225m² + 225m²

thus, area quad. ABCD= 450m²

First off, we know that it is a quadriletal. That means it has four sides. Lines BC and AD are same. That means:BC||AD(bc is parallel to ad)

So it is a rectangle. We know area of a rectangle is A=lb. In these measurements, it is A=30*15=450m^2.