Most students would like to the English Club. They want to improve their English.
①分别以B,C为圆心,以大于 12BC 的同样长为半径画弧,两弧相交于两点M,N;
②作直线MN交AB于点D,连结CD.
请回答:若CD=AC,∠A=50°,则∠ACB的度数为____.
□54÷75的商是两位数,方框中最小能填.