Grade 8 · 4 lessons and a review

Dilations and Right-Triangle Structure

Dilations change lengths by a common factor and preserve shape. Right-triangle relationships connect squared perpendicular lengths; their converse tests whether supplied side lengths support a right angle, including in a three-dimensional diagonal model.

Before you begin

Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.

Follow the lesson sequence

Lesson 3 of 4

Test a Right Angle from Three Sides

For a valid triangle, equality between the largest side’s square and the sum of the other two squares establishes a right angle opposite the largest side.

About 20 minutes, plus any extended practice

Open lesson 3

Review 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.

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Guest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.

Topic references

These references informed the topic selection. They do not certify complete standards alignment.