Area of square & Rectangle

Q.

$ABCD$ is an isosceles trapezium. If $\mathrm{AB}\parallel \mathrm{CD}$, $\mathrm{AB}=20\mathrm{cm}$, $\mathrm{CD}=10\mathrm{cm}$ and each of the non-parallel sides is $13\mathrm{cm}$, then find the area of trapezium.

Q.

The area of a rectangular field is $\text{1600 sqm.}$ If the length of the field is $\text{80m}$, find the perimeter of the field.