Maria had 2 yards of trim when she started.
Explanation:
Step 1:
All of the sides of the triangle is 22 inches long each.
The total length of the sides of the triangle

So the total length of the trim for the banner is 66 inches long.
If Maria still has
a foot of trim left, she had 6 inches of the trim left.
The length of the trim when she started
inches.
Step 2:
Now we need to convert the 72 inches into yards.
We have 1 inch = 0.0277778 yards.
So 72 inches

So Maria had 2 yards of trim when she started.