D(5, 7), E(4, 3), and F(8, 2) form the vertices of a triangle. What is m∠DEF?

What are the domain and range of f(x)=[1/5]x

Ineed asap. i cant understand this question i need someone to me right away

Darian wants to build a regulation size pool table that is 9 feet in length. he plans he ordered are 18 by 36 inches. what is the scale factor of the dilation he must use to build a regulation pool table