Triangle

A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments.

the area is as follow:
A = (1/2) x base side x heigth

Trapezoid

A trapezoid (in North America) or a trapezium (in Britain and elsewhere) is a quadrilateral, which is defined as a closed shape with four linear sides, that has one pair of parallel lines for sides. Some authors [1] define it as a quadrilateral having exactly one pair of parallel sides, so as to exclude parallelograms, which otherwise would be regarded as a special type of trapezoid, but most mathematicians use the inclusive definition.

The area formula is as follows:
A = h x ((a+b)/2)

Rhombus

A rhombus is an equilateral quadrilateral.

The Area formula
A = (DB x AC)/2

And The perimeter of a rhombus whose sides have length a is
P = 4a.

Circles

Circles are simple shapes of Euclidean geometry. A circle consists of those points in a plane which are at a constant distance, called the radius, from a fixed point, called the center.

The circumference of a square whose sides have length t is
C = 2 x pi x r, pi = 3.1415926535

And the area is
A = pi x r^2, pi = 3.1415926535.

Parallelogram

A parallelogram is a quadrilateral with two sets of parallel sides. The opposite sides of a parallelogram are of equal length, and the opposite angles of a parallelogram are congruent.

The area formula,
A=(1/2)B x A

Square

A square (regular quadrilateral) is a special case of a rectangle as it has four right angles and parallel sides.

The perimeter of a square whose sides have length t is
P = 4t.

And the area is
A = t^2.