# Course Updates for Basic Geometry in July 2021

We are excited to share that we've made significant enhancements to our **Basic Geometry **course. One consequence of adding this new content is that it may impact learners’ Mastery percentages.

When we add new content and remove old content, Mastery percentages often change because the **number of available skills changes**. For example, if you mastered 90 out of 100 skills in a course, and we added 10 new skills, your mastery skill count would then be 90 out of 110. This change would change your Mastery percentage from 90% to 82%.

With this specific course update, we expect that Mastery percentages will change by a maximum of **30%**. Most people will see a much smaller Mastery percentage change.

You can see exactly what content items we’ve added and removed below. Happy learning!

**Content Added**

*Articles*

*Exercises*

*Videos*

**Content Removed**

*Articles*

Graphing coordinates review |

Parallel and perpendicular lines review |

Quadrilateral problems on the coordinate plane |

Translations intro |

Vertical angles review |

Volume formulas review |

*Exercises*

Analyze shapes |

Analyze shapes by angles |

Area of rectangles with partial arrays |

Area of right triangles |

Area of trapezoids |

Benchmark angles |

Classify shapes |

Classify triangles by side lengths |

Compare shapes |

Complementary and supplementary angles (no visual) |

Constructing triangles |

Determine rotations |

Dilate points |

Dilations and properties |

Dilations: center |

Draw parallel and perpendicular lines |

Equal parts of circles |

Equal parts of rectangles |

Find missing length when given area of a parallelogram |

Find missing length when given area of a triangle |

Find perimeter when a side length is missing |

Find surface area by adding areas of faces |

Identify geometric solids (3D shapes) |

Identify parts of 3D shapes |

Identify quadrilaterals |

Identify shapes |

Name shapes 3 |

Ordering triangle sides and angles |

Partitioning rectangles |

Quadrants on the coordinate plane |

Quadrilateral problems on the coordinate plane |

Reflect points |

Reflecting points in the coordinate plane |

Rotate points |

Translate points |

Types of angles by measure |

Use area of squares to visualize Pythagorean theorem |

Volume with cubes with fraction lengths |

*Videos*

Another Pythagorean theorem proof |

Area of kites |

Area of trapezoids |

Bhaskara's proof of the Pythagorean theorem |

Coordinates of a missing vertex |

Coordinates of rectangle example |

Counting faces and edges of 3D shapes |

Cousin Fal's shape collection |

Dilations and properties |

Dilations: center |

Dimensions of a rectangle from coordinates |

Drawing parallel line segments |

Equal parts of circles and rectangles |

Example of shapes on a coordinate plane |

Finding circumference of a circle when given the area |

Finding distance with Pythagorean theorem |

Garfield's proof of the Pythagorean theorem |

Intro to quadrilateral |

Ordering triangle sides and angles example |

Partitioning rectangles |

Points and quadrants example |

Pythagorean theorem proof using similarity |

Quadrants of the coordinate plane |

Recognizing common 3D shapes |

Recognizing shapes |

Reflecting points in the coordinate plane |

Shapes and angles |

Translating points |

Volume with fractional cubes |