Geometry 9-12
A theater scene shop: constructions, rigid motions, congruence, proof, similarity, trigonometry, circles, coordinates and volume, for the set of the spring show.
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Geometry
A free online high-school Geometry course for Grades 9 to 12: definitions and constructions, rigid motions and symmetry, congruence, proof, dilations and similarity, right-triangle trigonometry, circles, coordinate geometry, equations of circles and parabolas, volume and geometric modeling, built around the set the crew designs for a community theater.
About the series
Geometry is a free online high-school geometry course for Grades 9 to 12 that needs only a tape measure, a straightedge, string and chalk, a protractor, graph paper, cardboard and scissors. Comet and Wren, the older crew, volunteer in the Scene Shop behind the neighborhood theater and build the set for the spring show, and every week's geometry makes a piece of the set work: the chalk grid and compass arcs, flats that slide and flip, matching braces, a parallelogram frame, a scale model, shadow measurements, the ramp angle, the turntable circle, the taped stage coordinates, the paint and foam props, the fabric and the honeycomb tiles. Students study a worked example, read and complete proofs, answer questions whose answers are computed and checked, and keep a Shop Book. The course maps week by week to the Common Core high-school geometry standards, states no fact about the world, and ends with Opening Night and a Shop Day run for the family.
In every course
- Grades 9 to 12, about 20 minutes a day
- Twelve weeks, from constructions and rigid motions to trigonometry, circles and volume
- Every question answer computed and checked, never typed by hand
- Proofs read, ordered and completed, never only memorized
- A hands-on Shop Lab every Wednesday with household materials
- The older crew, Comet and Wren, with Nova
- Maps to the Common Core high-school geometry standards
- A Saturday Shop Day for the family, with a note for the grown-up
- Free, start to finish. No card.
The course
The course is free, start to finish.
Questions families ask
What does it cost?
Nothing. Geometry is free from start to finish, with no card. A free parent account saves each student's progress.
What do we need at home?
A tape measure, a long straightedge or ruler, string and chalk or a pencil (the compass), a protractor, graph paper, cardboard, scissors, tape, a flashlight, paper cups and a jug of water. A grown-up holds any ladder.
Is this a full Geometry course?
It covers the Common Core high-school geometry standards: congruence, similarity, right triangles and trigonometry, circles, expressing geometric properties with equations, geometric measurement and dimension, and modeling with geometry. The optional (+) standards are not included. It is not a credit-bearing or accredited course.
What should a student know first?
Area and volume of simple shapes, the Pythagorean theorem, transformations on a grid, slope and linear equations, and solving a quadratic by square roots: the content of Geometry and Measurement Grades 6 to 8 and Algebra 1. The course reviews each as it goes.
Which standards does it cover?
The Common Core high-school standards G-CO, G-SRT, G-C, G-GPE, G-GMD and G-MG, listed week by week in the course.
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