19 topics
Geometry help, with the diagram drawn as it's explained
Geometry is the one math course where the answer often depends on seeing the figure correctly, which is exactly what a wall of text cannot give you. A proof that reads as impossible usually becomes obvious the moment someone draws the auxiliary line — and that is a drawing problem, not a reasoning problem.
Where students get stuck
I don't know how to start a two-column proof
Work backwards from the last line. Write the conclusion, ask what single fact would give it, and write that above. Usually the conclusion is a congruence, the fact above it is a triangle congruence theorem, and now the whole proof is just collecting three matching parts. Starting from the givens and hoping to arrive somewhere is what makes proofs feel like guesswork.
Congruent or similar — I mix them up
Congruent means same shape and same size, so corresponding sides are equal. Similar means same shape only, so corresponding sides are in a constant ratio. The tell is what the question gives you: if it hands you a scale factor, a midsegment, or two parallel lines cutting a triangle, it is a similarity problem. SSA is not a congruence theorem for the same reason it is ambiguous in the sine law.
Circle theorems all blur together
There are really only three ideas. An inscribed angle is half the central angle on the same arc — every 'inscribed angle' result including the semicircle right angle follows from it. A tangent meets a radius at 90°. And any two chords, secants, or tangents through one point satisfy the same product relationship. Nine named theorems, three ideas.
Surface area or volume — which formula?
Check the units the question wants. Square units means surface area, cubic units means volume. Beyond that, the mistake is usually not the formula but the slant height: a cone's lateral surface uses the slant height, its volume uses the perpendicular height, and the two are related by the Pythagorean theorem, not equal.
What's covered
Geometry topics you can work through with a tutor, generate practice on, or turn into flashcards and a study plan.
Reasoning and proof
- Definitions, postulates, and theorems
- Two-column, paragraph, and flowchart proofs
- Conditional statements, converse, and contrapositive
- Angle relationships in parallel lines
Triangles
- Triangle congruence: SSS, SAS, ASA, AAS, HL
- Similar triangles and scale factor
- The Pythagorean theorem and its converse
- Midsegments, medians, altitudes, and centroids
- Special right triangles
Polygons and circles
- Interior and exterior angle sums
- Properties of quadrilaterals
- Arcs, chords, and inscribed angles
- Tangents and secants
- Arc length and sector area
Coordinate and solid geometry
- Distance, midpoint, and slope
- Equations of lines, parallel and perpendicular
- Proving properties of figures on the coordinate plane
- Surface area and volume of prisms, cylinders, cones, and spheres
- Transformations and symmetry
Geometry questions
Can it actually draw the diagram, or does it just describe it?
It draws. The whiteboard sketches the figure by hand as it explains, so auxiliary lines, angle marks and labels appear in the order they matter. For geometry this is the difference between a usable explanation and a paragraph you have to re-draw yourself.
My proof is written but I think a step is missing. Can it check it?
Yes. Share your work and it will tell you which line is unjustified and what theorem the line needs, rather than writing a fresh proof from scratch. Getting a second proof does not teach you where yours broke.
Does it cover the coordinate geometry proofs too?
Yes — proving a quadrilateral is a parallelogram using slopes and midpoints, showing a triangle is right using the distance formula, and the rest of the coordinate-plane approach are all in scope.
Stuck on geometry right now?
Talk it through out loud, share your screen, and watch it worked out step by step on a whiteboard.
Start free — no card