$\beta \backslash beta$ ist Nebenwinkel zu $\alpha \backslash alpha$.

Damit gilt: $\alpha +\beta ={180}^{\circ }\backslash alpha+\backslash beta=180^\backslash circ$.

Folglich: $\beta ={180}^{\circ }-{110}^{\circ }={70}^{\circ }\backslash beta=180^\backslash circ-110^\backslash circ=70^\backslash circ$.

$\gamma \backslash gamma$ ist Scheitelwinkel zu $\alpha \backslash alpha$. Damit gilt: $\gamma =\alpha ={110}^{\circ }\backslash gamma=\backslash alpha=110^\backslash circ$.