Consider

A.ABC, with vertices
A (0,3),
B (0, 1), and C(-4,2), and
ADEF, with vertices D (0, 6), E (0, 2), and
F (8,4). Which transformations could be used to show that the triangles are similar? (1 point)
AABC is dilated by a scale factor of -2 and is reflected across the y-
axis.
• AABC is dilated by a scale factor of - and is reflected across the y-axis
• AABC is dilated by a scale factor of 1 and is reflected across the x-axis.
• AABC is dilated by a scale factor of 2 and is reflected across the y-axis.

1 answer

To determine which transformation(s) could be used to show that the triangles A.ABC and ADEF are similar, we first need to analyze the coordinates of the given vertices of both triangles.

Vertices:

  • Triangle ABC:

    • A(0, 3)
    • B(0, 1)
    • C(-4, 2)
  • Triangle DEF:

    • D(0, 6)
    • E(0, 2)
    • F(8, 4)

Step 1: Calculate side lengths

We can find the lengths of the sides of both triangles to check for similarity.

Triangle ABC:

  • AB = distance from A to B = |3 - 1| = 2
  • BC = distance from B to C = √((0 - (-4))² + (1 - 2)²) = √(4² + (-1)²) = √(16 + 1) = √17
  • AC = distance from A to C = √((0 - (-4))² + (3 - 2)²) = √(4² + 1²) = √(16 + 1) = √17

Triangle DEF:

  • DE = distance from D to E = |6 - 2| = 4
  • EF = distance from E to F = √((0 - 8)² + (2 - 4)²) = √((-8)² + (-2)²) = √(64 + 4) = √68
  • DF = distance from D to F = √((0 - 8)² + (6 - 4)²) = √((-8)² + (2)²) = √(64 + 4) = √68

Step 2: Compare the sides

From the calculations:

  • Triangle ABC side lengths: 2, √17, √17
  • Triangle DEF side lengths: 4, √68, √68

Step 3: Scale factor

To find a scale factor from triangle ABC to DEF:

  • The ratio of the corresponding sides AB and DE is 4/2 = 2.
  • The ratio of sides BC (√17) and EF (√68) can be simplified:
    • √68 / √17 = √(68/17) = √4 = 2.
  • The same holds for AC (√17) and DF (√68) as well (same ratio).

This shows that a dilation by a scale factor of 2 maintains the ratio of the corresponding sides.

Step 4: Reflection and transformations

Reflecting across the y-axis or x-axis and performing a dilation maintains the similarity.

Potential Transformation:

  1. AABC is dilated by a scale factor of 2 and is reflected across the y-axis.
    • Dilation by 2 scales all dimensions but also ensure that we have the same arrangement to match the vertices correctly.

The other options either suggest a negative scale transformation or incorrect reflection that don’t result in similarity, based on our calculations.

Conclusion:

The valid transformation showing that the triangles are similar is:

AABC is dilated by a scale factor of 2 and is reflected across the y-axis.