standard_description: Prove theorems about lines and angles. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.
problem_activity: Naja brought $20 to the corner store.
She spent $3.49 on candy.
She spent $5.79 on a Jamaican beef patty.
How much money did Naja have left?


aligns: no