Proofs & logical reasoning
Two-column and paragraph proofs, postulates, theorems, and how to structure an argument.
Geometry tutoring
Online Geometry Tutor — proofs, shapes, and reasoning.
Geometry asks students to justify their thinking, not just compute an answer. Northstar builds that reasoning habit using a shared digital whiteboard, so diagrams and proofs are drawn and discussed together in real time.
$50 / 60 minutes · No contracts · No required packages · No charge for missed sessions
What geometry sessions can cover
Angles, lines & triangles
Parallel lines, triangle congruence and similarity, and the classic angle relationships.
Circles
Arcs, chords, tangents, inscribed angles, and circle equations.
Coordinate geometry
Distance, midpoint, slope, and proving geometric facts using the coordinate plane.
Area, surface area & volume
Two- and three-dimensional measurement, including composite and rotated solids.
Right-triangle trigonometry
The Pythagorean theorem, special right triangles, and sine, cosine, and tangent.
Taught by a mathematics specialist
Northstar was founded by Joshua Lizardi, who holds an M.S. in Applied Mathematics, an M.S. in Data Analytics, a B.S. in Mathematics, and a Graduate Certificate in Applied Statistics, with 9+ years of teaching mathematics — including college and graduate-level instruction.
- Live one-to-one sessions through Zoom
- $50 per 60-minute session
- No contracts or required packages
- No charge for missed sessions
- Flexible scheduling
- Payment through Zelle
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Ready to make geometry proofs make sense?
Tell us what course your student is taking and what they need help with.
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