Answer:
C. 530 in²
Explanation:
To find the area of triangle DEN, use the formula for the area of a triangle:

In this case, the base of the triangle is side NE, which has a length of 26.5 inches. The height is the altitude from point D, which measures 40 inches.
Substituting the values in the formula, we get:

Therefore, the area of triangle DEN is 530 in².