1. Geometry
The shape of things to come…

2. Quadrilaterals

3. There are many different kinds of quadrilaterals
There are many different kinds of quadrilaterals. All of them have certain things in common. But most importantly they all have four sides!

4. A quadrilateral that has at least one pair of parallel sides.
Trapezoid:
A quadrilateral that has at least one pair of parallel sides.

5. This shape is also a trapezoid.
Parallelogram:
Opposite sides are parallel and of equal length. The opposite angles are equal.
This shape is also a trapezoid.

6. (It is also a parallelogram AND a trapezoid!)
Rhombus:
This parallelogram has four equal sides, but does not have four right angles.
(It is also a parallelogram AND a trapezoid!)

7. Rectangle: Has two parallel pairs of lines and four right angles.
(It is also a parallelogram AND a trapezoid.)

8. (It is also a parallelogram, a trapezoid, AND a rectangle!)
Square:
Has two parallel pairs of lines, four right angles, and all four sides are equal in length.
(It is also a parallelogram, a trapezoid, AND a rectangle!)

9. Triangles

10. Equilateral Triangle:
All three sides are equal. Each angle is equal to 60°.
Also called an acute-angled triangle.

11. It has a right angle (90°) in one of its corners.
Right Triangle:
It has a right angle (90°) in one of its corners.

12. Only two sides have the same length. Two angles are equal.
Isosceles Triangle:
Only two sides have the same length. Two angles are equal.

13. Each side is a different length. None of the angles are equal.
Scalene Triangle:
Each side is a different length. None of the angles are equal.