Final answer:
To find the length of AD in the parallelogram ABCD, measure the length of AB or BC, as they are equal. If AB is given as 10 units, then the length of AD is also 10 units.
Step-by-step explanation:
To determine the length of AD in the parallelogram ABCD, we need to find the length of the diagonal AD. In a parallelogram, opposite sides are equal in length. So, we can find the length of AD by measuring the length of AB or BC. If AB is given as 10 units, then the length of AD would also be 10 units.