What is the area of the two-dimensional cross section that is parallel to face ABC ?



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ft²
A right triangular prism containing dashed lines representing the hidden edges. The prism is resting on a triangular face, which is labeled D E F and contains right angle E. Side E F is labeled twelve feet. The top of the prism is labeled A B C and contains right angle B. Side A B is labeled five feet and side A C, which is the hypotenuse of the right triangular face, is labeled thirteen feet. The height of the prism is side C F labeled seventeen feet.

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Answer:

The area of the two-dimensional cross section is 30 feet²

Step-by-step explanation:

* Lets explain what is the right triangular prism

- The right triangular prism has five faces

- Two right triangular bases (cross sections)

- Three rectangular faces

- Its volume V = area of its base × its height

- Its surface area SA = the sum of the areas of the five faces

- The area of the triangular bases = 1/2 × base of Δ × height of Δ

* Lets solve the problem

- ABCFED is a right triangular prism

- Its two parallel bases are ABC and DEF

- Its bases are congruent right triangles

∴ AB = DE , BC = EF , AC = DF

∵ AB = 5 feet

∴ DE = 5 feet

- The two-dimensional cross section that is parallel to face ABC

  is the face DEF

∵ Δ DEF is right triangle , where angle E is a right angle

∴ DE and EF are the base and the height of Δ DEF

∵ DE = 5 feet ⇒ proved

∵ EF = 12 feet ⇒ given

∴ The area of Δ DEF = 1/2 × 5 × 12 = 30 feet²

∵ The two-dimensional cross section that is parallel to face ABC

  is the face DEF

* The area of the two-dimensional cross section is 30 feet²

Answer:

The area of the cross section is 30 feet².

Step-by-step explanation:

The area is 30, because you want to multiply 5 and 12, then multiply that by 1/2 to find the area of a right triangle.