Introduction

Consider construction workers. It is important for many of the things they build to be “square.” This usually involves using triangles or “right” triangles to ensure these constructions are “square”.

building under construction a right triangle is drawn over the image with measurements of 20 feet, 15 feet and 25 feet

Use the Squaring the Triangle to explore right triangles and the measure of the sides. You can adjust the measurement of BC and AC. Notice to the left of the triangle you will see the measurements of the sides, angles and you will see the “square” of each side. Do you notice something unique about the sum of the squares of BC and AC?

Lesson Objectives

Following successful completion of this lesson, students will be able to...

  • solve problems involving the sides of a right triangle using the Pythagorean Theorem.
  • prove a triangle is a right triangle using the converse of the Pythagorean Theorem.

Enduring Understandings

  • The Pythagorean Theorem establishes an essential relationship between the sides of a right triangle.

The above objectives correspond with the Alabama Course of Study: Geometry standards: 17 and 21.