Take the small side as x, the longer side is twice as long, i.e. 2x.
Perimeter = 2 small sides plus 2 long sides.
Perimeter = 2x + 2(2x)=30
Perimeter = 6x=30
x=5cm.
So small side is 5cm and long side is 10cm.
Area is one side multiplied by another.
Area = 5 * 10 = 50 square cm.