Question

ty uses a sailboat in a shadow play. when the sailboat moves closer to the screen, the shadow changes. the shadow represented by △abc changes to form △abc. what happens to the shadow? choose all that apply. it changes position. it changes shape. its vertices move along the rays. it changes size.

Explanation:

Step1: Analyze position change

When the sail - boat moves closer to the screen, the entire shadow moves, so its position changes.

Step2: Analyze shape change

The two triangles $\triangle ABC$ and $\triangle A'B'C'$ are similar, so the shape does not change.

Step3: Analyze vertex movement

The vertices of the shadow move along the rays of light from the light - source to the vertices of the sail - boat, so the vertices move along the rays.

Step4: Analyze size change

As the sail - boat moves closer to the screen, the shadow becomes larger, so it changes size.

Answer:

It changes position.
Its vertices move along the rays.
It changes size.