Given:

AB (say) = 11 cm

DC (say) = 25 cm

AD (say) = 15 cm

BC (say) = 13 cm

Draw AE ∥ BC

Now the trapezium is divided into a triangle ADE and a parallelogram AECB.

Since, AECB is a parallelogram

Therefore, AE = BC = 13 cm

And, AB = EC

DE = DC – EC( = AB) = 25 – 11 = 14 cm

Now,

We know that,

Area of a scalene triangle (∆AED) = √(s(s-AE)(s-ED)(s-AD))

Where,

⇒ s = 21 cm

Now,

Area of a scalene triangle = √(21cm × (21-13)cm × (21-14)cm × (21-15)cm)

= √(21cm × 8cm × 7cm × 6cm)

= √7056 cm²

= 84 cm²

Also,

Area of a triangle = 1/2 × base × height

⇒ 84 = 1/2 × 14 × height

⇒ height = 12 cm

Now,

Area of a parallelogram = base × height

= 11 cm × 12 cm

= 132 cm²

Now,

Area of Trapezium ABCD = Area of ∆ADE + Area of a parallelogram ABCE

= 84 cm² + 132 cm²

= 216 cm²