45-45-90 and 30-60-90 Triangles
Grade 10th Grade · Math · 45 min
What's Included
Learning Objective
I can calculate the side lengths of 45-45-90 and 30-60-90 triangles.
Warm-Up Video
Khan Academy · 5:42
45-45-90 triangle side ratios | Right triangles and trigonometry | Geometry | Khan Academy
Guided Notes
3 key concepts
- 1
A 45-45-90 triangle is also known as a right isosceles triangle because it has a right angle and two equal sides.
- 2
In a 45-45-90 triangle, if both legs are length x, the hypotenuse is equal to x√2.
- 3
The ratio of the sides in a 45-45-90 triangle is 1 to 1 to √2.
Practice Questions
10 questions · Multiple choice & Short answer
Exit Ticket
Quick comprehension check
“In a 45-45-90 triangle, one of the legs has a length of 7. What are the lengths of the other leg and the hypotenuse?”
Complete Lesson Package
Get all 3 ready-to-use resources:
Teacher Guide
Student Doc
Slides
