Answer:
It is given that in triangle XYZ, XY = 13, YZ=20, and XZ=25.Using the law of cosines, we have
CosC=\frac{a^2+b^2-c^2}{2ab}
cosZ=\frac{(YZ)^2+(XZ)^2-(XY)^2}{2(YZ)(XZ)}
CosZ=\frac{(20)^2+(25)^2-(13)^2}{2(20)(25)}
CosZ=\frac{400+625-169}{1000}
CosZ=\frac{856}{1000}
CosZ=0.856
Z=cos^{-1}(0.856)
Z=37.13^{\circ}
Step-by-step explanation:
