Why it trips people up
Many candidates under-study proofs and transformation criteria, then lose easy points on congruence/similarity logic.
Spatial reasoning + proof
Typical study load: ~25–40 hours
← All sections
Core · GEO
Geometry
Praxis 5165 Category III (~20%): Euclidean geometry, coordinate geometry, transformations, circles, measurement, and constructing valid arguments.
20 flashcards10 MCQs1 high-yield notes
Time
3 hours
MCQs / TBS
13 / 0
Score weight
20% MCQ · 0% TBS
of exam
n/a
Common traps
- Assuming figures are to scale
- Mixing up AA similarity with SSA non-congruence
- Forgetting units / dimensional analysis in measurement
How to study GEO
- 1
Memorize congruence and similarity criteria with one diagram each.
- 2
Practice short two-column or paragraph proofs daily.
- 3
Connect coordinate formulas to geometric meaning (distance, midpoint, slope).
- 4
Review circle theorems and right-triangle trig links.
Blueprint content areas
Weights are ETS blueprint ranges. Use them to prioritize — do not ignore low-weight areas entirely, but spend more reps where the exam spends more score.
III — Geometry
20%- • Congruence & similarity
- • Proof & constructions
- • Coordinate geometry
- • Circles & right triangles
- • Transformations & measurement
GEO high-yield notes
Study these, then drill the GEO flashcards and MCQs.
GEO · High-yield
Congruence vs similarity checklist
Keep a one-page cheat sheet of SSS/SAS/ASA/AAS vs AA similarity, and remember SSA is dangerous.
- Congruence criteria need corresponding parts carefully matched.
- Similar ⇒ proportional sides; congruent ⇒ equal sides.
- Isometries (translate/rotate/reflect) preserve distance; dilations do not.
Exam tip: On diagrams, mark given ticks/arcs before hunting a criterion.