What is the ratio of angle measures of a right-angled isosceles triangle?

State which of the followings are triangle

$\overline{\mathrm{AB}}=7\mathrm{cm}, \overline{\mathrm{BC}}=8\mathrm{cm}, \overline{\mathrm{AC}}=7\mathrm{cm}$

State which of the followings are triangle

$\overline{XY}=50 \mathrm{cm}, \overline{YZ}=25 \mathrm{cm}, \overline{XZ}=25 \mathrm{cm}$

State which of the followings are triangle

$\overline{MN}=100 \mathrm{cm}, \overline{ON}=60 \mathrm{cm}, \overline{OM}=40 \mathrm{cm}$

State which of the followings are triangle

$\overline{PQ}=17 \mathrm{cm}, \overline{QR}=12 \mathrm{cm}, \overline{PR}=27 \mathrm{cm}$

State which of the followings are triangle

$\overline{XY}=25 \mathrm{cm}, \overline{YZ}=25 \mathrm{cm}, \overline{XZ}=45 \mathrm{cm}$

State which of the followings are triangle

$\overline{MN}=15 \mathrm{cm}, \overline{ON}=10 \mathrm{cm}, \overline{OM}=20 \mathrm{cm}$

State which of the following are triangle

$\angle A=60°, \angle B=60°,\angle C= 60°$.

State which of the following are triangle

$\angle P=80°, \angle Q=70°,\angle R= 70°$.