The unequal side of an isosceles triangle is 3cm more than one of its equal sides. If the perimeter of the triangle is 18cm, find the length of the three sides.

Let the length of the equal sides be x cm.
Then the length of the unequal sides will be (x + 3) cm.
Perimeter of an isosceles triangle is 18.∴ x + x + 3 + x = 18
3x + 3 = 18
3x = 15 ∴ x = 5
Therefore the equal sides of the triangle is 5cm and unequal side is 8cm.