1. Steam Project
William Alvira

2. Definitions of quadrilaterals
Parallelogram is a four sided plane rectilinear figure with opposite sides parallel.
Rectangle a plane figure with four straight sides and four right angles, especially one with unequal adjacent sides, in contrast to a square.

3. Definitions on planes
A rhombus plural rhombi or rhombuses, is a simple (non-self-intersecting) quadrilateral all of whose four sides have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length
Square a plane figure with four equal straight sides and four right angles

4. Definitions
Trapezoid is a quadrilateral with only one pair of parallel sides
Isosceles trapezoid a convex quadrilateral with a line of symmetry bisecting one pair of opposite sides, making it automatically a trapezoid

5. Definitions on Basic postulates, Isosceles triangle theroms, and single angle therom