Because y = ax is maximum when a = x
rectangle
A "parallelogram" technically is a shape where opposite sides are equal and any shape with four sides is a "quadrilateral". Every square has four sides of equal length, so a square is both a parallelogram and a quadrilateral. A rhombus(or diamond shape) can have four sides of equal length and can be a parallelogram as well, so either are possibilities.
pentagon
A regular pentagon has five sides of equal lengths.
Any regular shaped polygon has equal angles and equal sides
A shape with sides of equal length is referred to as REGULAR. This has 7 letters.
a shape with 10 sides is called a decagon.
a square
A rhombus.
a square
Trapizium
This shape is called an icosikaitera. All of the sides of the icosikaitera are all of the same equal length.