Marilyn is having shelves installed to create a corner pantry. The length of one wall is 21 inches and the length of the other wall is 25 inches. The contractor who is making the shelves, which are shaped like right triangles, needs to know the measure of the angle opposite the short side of the pantry, m. What is the measure of that angle? Round your answer to the nearest degree.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

30 feet

step-by-step explanation:

that would be 2 1/2 * 12

= 24 + 6

= 30 feet   (answer)