Question 377438
find the distance between the points 
a(3,-7)and b(-5,9).

sol'n:
  distance(d) = sq. root of [(x2-x1)^2+(y2-y1)^2]
  so, at pt. P1(3,-7)& P2(-5,9)
  d = sq. root of [(-5-3)^2 + (9+7)^2]
  d = sq. root of [64 + 256]
  d = sq. root of (320)
  d = 17.888 units ----answer