Lesson: Pythagorean Inequality Theorem Mathematics • 8th Grade

In this lesson, we will learn how to determine whether an angle in a triangle is acute, right, or obtuse by using the Pythagorean inequality.

Lesson Plan

Students will be able to

understand that in a triangle with vertices , , and , if
- , then is a right angle,
- , then is an obtuse angle,
- , then is an acute angle,
classify whether an angle or triangle is acute, right, or obtuse by using the Pythagorean inequality theorem,
find the type of the greatest angle in a triangle given the side lengths.

Q1:

In triangle , . What type of angle is ?

Q2:

In triangle , . What type of angle is ?

Q3:

In triangle , . What type of angle is ?