Find a diagonal with the Pythagorean theorem
Use a right-triangle relationship and check which side is the hypotenuse.
Open lesson 1Distances and Scaled Designs
Use right triangles, coordinates, and similarity to reason about fictional designs.
Before you begin
- Evaluate squares and positive square roots.
- Read coordinates, multiply decimals, and use rectangle area and perimeter formulas.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Find a Distance Between Coordinates
Build a right triangle from coordinate differences.
Open lesson 2Scale Corresponding Lengths
Use one scale factor for corresponding sides of similar figures.
Open lesson 3Separate Length Scaling from Area Scaling
Explain why perimeter scales by a factor and area by its square.
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.