Answer:
Sasha's grandma will need 48 square feet of fabric to sew the umbrella.
Explanation:
Since Sasha's grandma is going to sew an umbrella for Sasha, which will be made of 4 identical triangles, if each triangle is 3 feet long and 4 feet high, to determine how many square feet of fabric does Sasha's grandma need, the following calculation must be done:
(3 x 4) x 4 = X
12 x 4 = X
48 = X
Therefore, Sasha's grandma will need 48 square feet of fabric to sew the umbrella.