Final answer:
The new triangle formed when a ladder slides down a wall, changing its angle, is not congruent to the original triangle because the angle formed by the ladder has changed, altering the shape of the triangle.
Step-by-step explanation:
The answer to whether the new triangle formed when the top of the ladder slides down and the bottom slides out is congruent to the original triangle is A. No, because the angle formed by the ladder changed. Congruent triangles are those that are identical in shape and size, but when the ladder slides, both the angle and the position of the ladder change, while the length of the ladder remains the same. As the angle changes, the corresponding sides and angles of the original and new triangle no longer have the same measurements, implying that the two triangles formed are no longer congruent.
It's important to understand that the significance of the situation does not depend on the length of the ladder but rather on the angles and the static conditions that prevent it from slipping such as the coefficient of static friction and the reaction forces. A translation or rotation that maintains the ladder's original angle with the floor and does not alter the static conditions could potentially result in congruent triangles, but this is not the case when the angle itself changes due to sliding.