these are word for word out of the book. (d(A,B) means the distance from A to B) 1. if A, B, and C are three points in a plane, d(A,B) = 3 and d(B,C) = 2, what can you say about d(A,C)? for this one I just used the distance fomula using the lines lengths... so i did: d(A,C) = square root of(3^2 + 2^2) and i got the square root of 13... is this correct. the second one i have really no clue how to do. 2. let P1 = (-1,2) and P2 = (0,0). find the point P3 in quadrant 1 such that {P1,P2,P3} are vertices of an equilateral triangle.