- Topics At a Glance
- Basic Shapes & Angles
- Angles
- Parallel Lines & Transversals
- Polygons
- Triangles
- Quadrilaterals
- Angles in a Polygon
- Circles
- Similar Figures
- Perimeter & Circumference
- Area (Polygon, Triangle, Circle, Square)
- Area Formulas
- Area of Irregular Shapes
- 3D Objects (Prisms, Cylinders, Cones, Spheres)
- Volume of Prisms & Cylinders
- Volume of Pyramids & Cones
- Volume of Spheres
- Surface Area
- Pythagorean Theorem
Introduction to Angles:
Not to be confused with angels, angles are the pointed corners of shapes. Angles can be named three different ways.
This angle could be named any of these ways:
(counterclockwise)
(clockwise)
(just the vertex)
Look Out: when naming an angle using three letters, the vertex must always be the middle letter!
Types of Angles
| Name | Description | Example |
| Acute Angle | An angle less that 90°.
Lame joke: this angle is so small and a-cute! |  |
| Obtuse Angle | An angle greater than 90°, but less than 180°. |  |
| Right Angle | An angle that is exactly 90°.
This is commonly denoted with a small box in the corner. |  |
| Straight Angle | A 180° angle. It's - you guessed it - a straight line. |  |
| Supplementary Angles | Angles that add up to 180°. are supplementary angles. |  |
| Complementary Angles | Angles that add up to 90°.
 are complementary.
|  |
| Vertical Angles | When two lines intersect, opposite angles are called "vertical angles". Vertical angles are congruent.   |  |
Oh, btw, congruent angles are two or more angles that have the same measurement.
Angles Practice:
Example 1
|
are vertical angles, so they are congruent.
are straight. 
Refer to the following diagram to answer questions 1-4
Exercise 1
Name two sets of complementary angles.
Exercise 2
Name two sets of vertical angles.
Exercise 3
Name four obtuse angles.
Exercise 4
Name four right angles.
