## Elementary Geometry for College Students (5th Edition)

(2a,2b) and (2c,2d) Using theorem 10.1.2 Midpoint formula M = ($x_{m}, y_{m})$ = ($\frac{x1+x2}{2}$, $\frac{y1+y2}{2}$) M = ($\frac{2a+2c}{2}$, $\frac{2b+2d}{2}$) = ((a+c),(b+d))