A shape that has three unequal sides is a scalene triangle. A shape that has four unequal sides is a quadrilateral. A shape that has more than four unequal sides is an irregular polygon.
A five-sided shape is a pentagon. A six-sided shape is a hexagon. A heptagon is a seven-sided shape, and an octagon is an eight-sided shape. Each of these can have unequal sides and can all generally be called irregular polygons if the sides are not equal to one another. A regular polygon has equal lengths on each side and equal angles. Where the shape has unequal sides, it also usually has unequal angles.