Special right triangles: 45-45-90 and 30-60-90
Start lessonBegins with Exercise · Practice
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
- Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
- Guided Notes →One page your students fill in and keep.
- Exit Ticket →Three items at the end of class. No student accounts.
- Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
- Homework →Assign practice; it grades itself.
"Solve problems in a variety of contexts using: ... • properties of special right triangles."
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"Solve problems in a variety of contexts using: ... • properties of special right triangles."
What you'll learn
- Find any missing side of a 45-45-90 or 30-60-90 triangle given one side
- Match each side to its place in the ratio: 1 : 1 : sqrt(2) with sqrt(2) on the hypotenuse; 1 : sqrt(3) : 2 with the short leg opposite 30 degrees and the long leg opposite 60 degrees
- Derive the 45-45-90 ratio by cutting a unit square along its diagonal
- Derive the 30-60-90 ratio by bisecting an equilateral triangle
- Identify a special right triangle embedded in a larger figure (square, equilateral triangle, rectangle, regular hexagon) and use it to find a length
Slides
Step through the lesson, or watch it as a narrated video
Slides
In development
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Practice
Try it on your own
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