A dolphin was swimming 28 meters below the ocean's surface. It changed its depth to avoid a predator and ended up 21 meters below the surface.
What was the change in the dolphin's depth?

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

When the ball has traveled a distance of

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?