Inside or Outside?
Classify each of the eight angles as INTERIOR or EXTERIOR and justify by position relative to the parallel lines.
Interior/Exterior
Best: — 0 attempts
Same Side or Opposite Side?
Given two angles, decide whether they lie on the same side or opposite sides of the transversal.
Same/Opposite
Best: — 0 attempts
Requires: M1
Find the F
Identify corresponding angle pairs, distinguish positional classification from the measure consequence, and state the theorem.
Corresponding
Best: — 0 attempts
Requires: M1, M2
Trace the Z
Identify alternate interior and alternate exterior pairs and remove reliance on the mnemonic.
Alternate Interior Alternate Exterior
Best: — 0 attempts
Requires: M3
Build the C
Identify same-side interior and same-side exterior pairs and reconstruct the supplementary equation.
Same-Side Interior Same-Side Exterior
Best: — 0 attempts
Requires: M4
Spot the X
Distinguish vertical angles from linear pairs at one intersection and justify vertical congruence via supplements.
Vertical Linear Pair
Best: — 0 attempts
Requires: M5
Which Theorem?
Drag the correct theorem to a given angle pair and complete a structured justification sentence.
Corresponding Alternate Interior Alternate Exterior Same-Side Interior Same-Side Exterior Vertical
Best: — 0 attempts
Requires: M6
One Angle Unlocks All
From one known angle, determine all eight measures via a reasoning chain, then explain why only two measures appear.
Corresponding Alternate Interior Vertical Linear Pair
Best: — 0 attempts
Requires: M7
Parallel or Not?
Use converse theorems to decide whether lines are parallel from angle evidence, distinguishing forward from converse.
Converse Theorems
Best: — 0 attempts
Requires: M8
Algebra from Geometry
Classify geometry first, select the theorem, then derive and solve the equation one step at a time.
Algebra Bridge
Best: — 0 attempts
Requires: M9
Can You Prove It?
Build a two-column proof by dragging statements and reasons into logical order, rejecting distractors.
Proof
Best: — 0 attempts
Requires: M10
Similarity Detective
Decide similar / not similar / not enough info, then name the criterion and the correspondence.
AA Similarity SAS Similarity SSS Similarity
Best: — 0 attempts
Requires: M11
Match the Vertices
Drag-match vertices by structure, construct the similarity statement, and reason about order.
Vertex Correspondence
Best: — 0 attempts
Requires: M12
Build the Proportion
Construct valid proportions from correspondence, build the reciprocal, and diagnose an invalid mixed proportion.
Side Correspondence Proportions
Best: — 0 attempts
Requires: M13
Parallel Lines Create Similar Triangles
Connect DE∥BC → corresponding angles → AA → △ADE~△ABC → proportional sides → solve a missing side.
Parallel → Similarity Bridge AA Similarity Proportions
Best: — 0 attempts
Requires: M14
Geometry Grand Challenge
Cumulative multi-step: classify transversal, transfer angle, find triangle angles, exterior angle, AA, correspondence, proportion, solve, verify, explain.
Corresponding AA Similarity Proportions Proof Parallel → Similarity Bridge
Best: — 0 attempts
Requires: M15