(2017年北京中考数学第28题)在等腰直角△ABC中,∠ACB=90°,P是线段BC上一动点(与点B,C不重合),连接AP,延长BC至点Q,使得CQ=CP,过点Q作QH⊥AP于点H,交AB于点M.(1)若∠PAC=α,求∠AMQ的大小(用含α的式子表示):(2)用等式表示线段MB与PQ之间的数量关系,并证明.这道题是一道几何综合题,从基本的几何元素出 In the isosceles right angle △ ABC, ∠ACB = 90 °, P is the line moving point on the BC (with points B, C do not coincide), connect the AP, extend the BC to the point Q, (1) If ∠PAC = α, find the size of ∠AMQ (with α expression): (2) With =PAC = α, The equation shows the quantitative relationship between the line segments MB and PQ, and proves that this question is a geometric synthesis problem, from the basic geometric elements