You might try squaring a few numbers; i.e., 2^2= 4
3^2 = 9
4^2 = 16
5^2 = 25
Now look at the prime numbers; i.e., 2, 3, 5,7,11,13,17,19,23, etc.
Which of the "squares" will divide evenly into 48? Add those sides together to see if the sum is a prime number.
so the area must be 48 square units, where the length and width are whole numbers
so factors of 48 would be
the sums of these possibilites are
49,26,19,16, and 14
of these only 19 is a prime number
so the length of Jennifer's triangle is 16 and its width is 3