## Geometry: Common Core (15th Edition)

a) use the midpoint formula $M(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$ substitute $M(\frac{5+17}{2},\frac{9+29}{2})$ $M(\frac{22}{2},\frac{38}{2})$ $M(11,19)$ b) use the distance formula to show the distance is the same from the midpoint to each endpoint. $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$ $d=\sqrt{(5-11)^2+(9-19)^2}$ $d=\sqrt{(-6)^2+(-10)^2}$ $d=\sqrt{36+100}$ $d=\sqrt{136}$ $d=11.7\checkmark$ $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$ $d=\sqrt{(17-11)^2+(29-19)^2}$ $d=\sqrt{(6)^2+(10)^2}$ $d=\sqrt{36+100}$ $d=\sqrt{136}$ $d=11.7\checkmark$