Cho ∆MPQ co goc PMQ=90°. Duong thang MH vuong goc voi PQ tai H. Tren duong vuong goc voi PQ tai P lay diem D ko cung nua mat phang bo PQ voi diem M sao cho MH=PD
Chung minh ∆ MHP=∆DPH
Hai duong thang MP va DH co song song ko? Tai sao?
Tinh goc MQP, biet goc PMH=30°