How do area models show partial products​

The standard distance between studs in a house is 1.5 feet. if you have a set of blueprints for a house that mark every 1.5 feet with 2 in., by how many inches will a 13-foot wall be represented?

In the figure below, triangle rpq is similar to triangle rts. what is the distance between p and q? a. 24 b. 42 c.50 d. 54

Find the maximum value of p= 4x + 5y subject to the following constraints :