单选题
RT=
【正确答案】
【答案解析】12.5.The triangles PQS and PRT are similar because they share ∠TPR and each have a right angle. Because they are similar, the ratios of their heights to their bases are equal: 
, thus 
. By multiplying both sides of the equation by 15, you get 
, thus . By multiplying both sides of the equation by 15, you get