What's is the the answer to a?

Well, you need to add together how much wood you need. one side is 4 1/4 long & the other side is 5 1/8 long. you need to find a common denominator before you add.
multiply the numerator and denominator of the first number by 2.
4 1/4 × 2 = 4 2/8
multiply the numerator and denominator of the second number by 1 because you already have common denominators.
5 1/8 × 1 = 5 1/8
now you can add.
4 2/8 + 5 1/8 = 9 3/8
9 3/8 does not simplify.
therefore Mrs. Edwards only needs to buy the smallest amount of wood available, which is 12 inches.