Final answer:
Ms. Lopez can make 10 snow angels.
Step-by-step explanation:
To find out how many snow angels Ms. Lopez can make, we need to convert the length of her backyard from feet to yards. Since there are 3 feet in 1 yard, the length of Ms. Lopez's backyard in yards is 30/3 = 10 yards. Since each snow angel is one yard, Ms. Lopez can make 10 snow angels.