Find the missing length the triangles are similar

An astronaut drops a rock into a crater on the moon. the distance, d(t), in meters, the rock travels after t seconds can be modeled by the function d(t)0.82. what is the average speed, in meters per second, of the rock between 5 and 10 seconds after it was dropped?

Empty box + box + empty box fill in the box is equal to 30 how

Is it true or false i’m trying to pass this test so i can leave school