The area of the two-dimensional cross section that is parallel to face ABC.that is Area of Δ DEF = 84 ft²

Step-by-step explanation:

Given : A triangular prism with some side measurement.

We have to find the area of the two-dimensional cross section that is parallel to face ABC.

Since, the cross section that is parallel to face ABC.

Since, face parallel to ABC is DEF .

And DEF is a triangle with ∠ E = 90°

So, Area of right angled triangle is 1/2 times base times height.

Base = 24 ft

and height is 7 ft

So, Area of Δ DEF = 1/2 times 24 times 7

Simplify , we have,

Area of Δ DEF = 84 ft²

Thus, The area of the two-dimensional cross section that is parallel to face ABC.that is Area of Δ DEF = 84 ft²