Question

The rule is applied to ΔABC.

On a coordinate plane, 5 triangles are shown. Triangle A B C has points (2, negative 4), (4, negative 4), (4, negative 2). Triangle 1 has points (negative 4, 2), (negative 4, 4), (negative 2, 4). Triangle 2 has points (negative 3, 3), (negative 1, 3), (negative 1, 1). Triangle 3 has points (1, 1), (1, 3), (3, 3). Triangle 4 has points (2, 4), (4, 2), (4, 4).
Which triangle shows the final image?

1
2
3
4

Answer 1

Reflect across the line y = x (swap x and y):

(2, −4) → (−4, 2)
(4, −4) → (−4, 4)
(4, −2) → (−2, 4)

Those are exactly the vertices of Triangle 1.

Answer: 1