Use the image to answer the question.

An illustration shows two right angled triangles. The first triangle shows a base of 4 meters and a perpendicular side of 3 meters. The second triangle shows a base of 10 meters and a perpendicular side of 9 meters. A right angle symbol is shown at the vertex between the perpendicular side and the base.

Archer is sewing a triangular flag. He starts with the scale drawing on the left and plans to enlarge the flag to match the picture on the right. What will be the area of the completed flag in square feet?

(1 point)
Responses

72 square feet
72 square feet

54 square feet
54 square feet

6 square feet
6 square feet

108 square feet

1 answer

To find the area of the completed flag that Archer is making, we first need to calculate the area of each triangle and then determine how the area changes when enlarging the flag.

  1. Calculate the area of the first triangle (4 meters base and 3 meters height): \[ \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 4 \times 3 = 6 \text{ square meters} \]

  2. Calculate the area of the second triangle (10 meters base and 9 meters height): \[ \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 10 \times 9 = 45 \text{ square meters} \]

  3. Compare the two triangles:

    • The area of the second triangle is significantly larger than the first triangle. The second triangle is, in fact, a scaled-up version of the first triangle.
  4. Determine the scale factor: The scaling factor for the base from 4 meters to 10 meters is: \[ \text{Scale factor} = \frac{10}{4} = 2.5 \] Similarly, for the height from 3 meters to 9 meters, the scaling factor is: \[ \text{Scale factor} = \frac{9}{3} = 3 \]

  5. Determine the area of the enlarged triangle: When an object is scaled, the area scales by the square of the scaling factor. In this case, let's take the height scale factor (3), since it matches uniformly: \[ \text{New Area} = \text{Original Area} \times (\text{scale factor})^2 = 6 \times 3^2 = 6 \times 9 = 54 \text{ square meters} \]

  6. Conversion from square meters to square feet: Since 1 square meter is approximately 10.764 square feet, we convert the area: \[ \text{Area in square feet} = 54 \times 10.764 \approx 581.3 \text{ square feet} \]

  7. Compare to options provided (response choices): Assuming there is some misalignment in scaling or an exact enlargement value given directly leads to an area of 72 square feet from another calculation, the closest calculated values indicate that the expected is closer to:

Among the options given:

  • 72 square feet is the closest but not an arithmetic match.

Thus, given the choices, the thoughtful choice leads to 72 square feet as a probable area for Archer's completed flag.

Final answer: 72 square feet.