Which fact is not used to prove that pqr is similar to str? segments st and pq are parallel. angle p is congruent to itself due to the reflexive property. rp is a transversal line passing st and pq. angles rts and rqp are congruent due to the corresponding angles postulate.

water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. at this point, equilibrium is reached. in an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

hope this < 3

60: 45 =12: 9 =4: 3 so the answer is 4: 3