Geometry Foundations Checkpoint
A free Geometry lesson from the “Geometry Foundations” unit, with a worked example and practice problems including step-by-step solutions.
This checkpoint mixes the opening geometry skills: vocabulary, diagram reading, angle relationships, parallel lines, transversals, and triangle angle sums. In Geometry Foundations, students need to read the diagram, name the relationship, choose a theorem or formula, and justify why the result follows. The expanded practice now includes fluency, transfer, cumulative review, and proof-style reasoning so Geometry feels connected instead of isolated by topic.
What you'll learn
- Review angle relationships
- Use parallel-line facts
- Solve triangle angle problems
Worked example
Problem. Two same-side interior angles are 118 degrees and x. Find x.
- Same-side interior angles are supplementary.
- Write 118 + x = 180.
- x = 62.
- Connect the result back to Geometry Foundations Checkpoint so the geometric relationship is explicit.
Answer: 62
Lesson preview: this page shows 5 practice items. The interactive activity contains 25 practice items and 25 quiz items (multiple choice and typed response). Counts include repeated prompts and variants.
Practice problems
1. Two lines that meet at 90 degrees are...
Choices: Perpendicular · Parallel · Collinear · Congruent
Show solution
- Perpendicular lines form right angles.
Answer: Perpendicular
2. An angle is complementary to 47 degrees. What is its measure?
Show solution
- 90 - 47 = 43.
Answer: 43
3. An angle is supplementary to 133 degrees. What is its measure?
Show solution
- 180 - 133 = 47.
Answer: 47
4. Vertical angles measure 6x and 114 degrees. Find x.
Show solution
- 6x = 114.
Answer: 19
5. Same-side interior angles include 101 degrees. What is the other angle?
Show solution
- 180 - 101 = 79.
Answer: 79
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