Question

Point A is located at (−1,−5). The midpoint of line segment AB is point C(2,3). ​ What are the coordinates of point B ?

Answer 1

For a segment AB, the coordinates of the middle point C are:

xc=(xa+xb)/2,

yc=(ya+yb)/2.

Now, you know points A and C. Thus we get:

xb=2×xc-xa

yb=2×yc-ya

With numerical values:

xb=2×2-(-1)=4+1=5

yb=2×3-(-5)=6+5=11

Answer: B(5, 11)