Unit 7 · Right Triangles and Trigonometry

7.3Distance Formula and Right Triangles

Quick Answer

The distance formula d = √((x₂−x₁)² + (y₂−y₁)²) is derived directly from the Pythagorean Theorem applied to a right triangle in the coordinate plane.

Essential Question

How does the Pythagorean Theorem become the distance formula when applied to a right triangle in the coordinate plane?

Learning Goals

  • 1Derive the distance formula from the Pythagorean Theorem.
  • 2Apply the distance formula to find the distance between two points.
  • 3Classify triangles in the coordinate plane using side lengths.

Key Vocabulary

Distance formula

d = √((x₂−x₁)² + (y₂−y₁)²); derived from the Pythagorean Theorem.

Full lesson content coming soon

Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.