How do you determine if two triangles are similar?

Which statements regarding the diagram are true? check all that apply.

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?