Let f be the fathers age and let s be the sons age
f = 60 s = 30
when f = 45
s = 15 which is only a third if his fathers age
when f = 40
s = 10 which is a quarter of his fathers age
therefore when his father was 4 times his age, the son was 10
The area of a triangle is 180 becuase each area is 60
The point (3,4) is the answer
AC should be 28 because 12 is 8 less than 20 and and 28 is 8 more than 20