Key takeaway: Geometry vocabulary for Grade 10 includes 50 terms such as conditional statement, CPCTC, centroid, AA similarity, SOHCAHTOA, inscribed angle and Cavalieri’s principle.
High school geometry asks students to prove, not only to measure. That means a precise vocabulary: a converse is not the same as the original statement, and SAS is not the same as SSA. This geometry vocabulary list for Grade 10 sets out each word clearly.
It covers the building blocks of proof, rigid transformations, congruent and similar triangles, trigonometric ratios, circles, volume and probability. Every page has a labeled figure, so the definition can be seen as well as read.
50 terms on this page, each with a definition, a figure and a worked example.
Geometry Vocabulary: the full list
Geometry and Measurement
- AA Similarity G-SRT.A.3
- Angle G-CO.A.1
- Angle Bisector G-CO.D.12
- Arc (Circle) G-C.A.2
- Arc Length G-C.B.5
- Area of a Sector G-C.B.5
- Cavalieri's Principle G-GMD.A.1
- Central Angle G-C.A.2
- Centroid G-CO.C.10
- Chord G-C.A.2
- Circumcenter G-C.A.3
- Conditional Statement G-CO.C.9
- Congruent Triangles G-CO.B.7
- Converse G-CO.C.9
- CPCTC G-CO.B.7
- Equation of a Circle G-GPE.A.1
- Focus and Directrix G-GPE.A.2
- HL Theorem (Hypotenuse-Leg) G-SRT.B.5
- Incenter G-C.A.3
- Inscribed Angle G-C.A.2
- Isosceles Triangle Theorem G-CO.C.10
- Line Segment G-CO.A.1
- Midpoint Formula G-GPE.B.6
- Midsegment of a Triangle G-CO.C.10
- Parallel Lines G-CO.C.9
- Parallelogram G-CO.C.11
- Perpendicular Bisector G-CO.C.9
- Perpendicular Lines G-GPE.B.5
- Point, Line and Plane G-CO.A.1
- Ray G-CO.A.1
- Rhombus G-CO.C.11
- Rigid Transformation G-CO.A.5
- Same-Side Interior Angles G-CO.C.9
- Similar Triangles G-SRT.B.5
- Solid of Revolution G-GMD.B.4
- Tangent to a Circle G-C.A.4
- Triangle Congruence (SSS, SAS, ASA, AAS) G-CO.B.8
- Two-Column Proof G-CO.C.9
- Volume of a Pyramid G-GMD.A.3
Trigonometry
- Angle of Elevation and Depression G-SRT.C.8
- Cosine G-SRT.C.6
- Law of Cosines G-SRT.D.10
- Law of Sines G-SRT.D.10
- Radian G-C.B.5
- Sine G-SRT.C.6
- SOHCAHTOA G-SRT.C.6
- Special Right Triangles G-SRT.C.6
- Tangent (Trigonometric Ratio) G-SRT.C.6
Probability and Counting
- Conditional Probability S-CP.A.3
- Independent Events S-CP.A.2