AM+AC = AB = AM+BM ⇒AC ≡ BM
BM +BD = AB = AM+BM ⇒BD≡ AM
∡CAM =∡DBM = 90
⇒ (L.U.L.) ΔACM ≡ΔMBD ⇒ CM ≡ MD, ∡ ACM ≡ ∡ DMB, ∡AMC ≡ ∡ BDM
Dar ∡ ACM + ∡AMC = 90 ⇔∡ DMB + ∡AMC= 90 ⇒∡CMD =90
CM ≡ MD ⇒ ΔCDM - isoscel ⇒∡MCD=∡MDC= (180-∡CMD)/2= (180-90)/2=45
DECI: ∡CMD =90, ∡MCD=∡MDC= 45