Help me answer question 1 a, b and c please !

1)Two hikers, Zaphod and Ford, are standing on the edge of a river at point A directly across from tree T. They mark off a certain distance to point B, where Zaphod remains. Ford then walks the same distance to point C. Then he turns and walks directly away from the river to point D, where he can see Zaphod lined up with the tree. a)Is AABT = ACBD ? Why or why not? b)If they know the distance from B to C is 4 metres and the distance from C to D is 5 metres how far is it from their original position across the river to the tree? T river C B c)What is the distance from D to T