fie AM⊥DC , BN⊥DC=> AM,BN-> inaltimi in trapezul ABCD
AM=BN
A=(AB+DC)*AM/2<=>24√2=(2√2+6√2)*AM/2<=>24√2=4√2*AM=> AM=24√2/4√2=6 cm
AM=BN=6 cm
AB=MN=2√2 cm
DM=NC=(DC-MN)/2=(6√2-2√2)/2=4√2/2=2√2 cm
In ΔAMD , m(∡M)=90°=> ctg D=DM/AM=2√2/6=√2/3