In $\triangle PQR$,$\angle R = \angle P$,$QR = 4 \, cm$,and $PR = 5 \, cm$. Then the length of $PQ$ is (in $cm$):

In $\Delta ABC$,$AB = AC$ and $\angle B = 75^{\circ}$,then $\angle C = \dots$ (in $^{\circ}$)

$\angle ACD$ is an exterior angle of $\Delta ABC$. If $AB = AC$ and $\angle B = 70^{\circ}$,then $\angle ACD = \dots$ (in $^{\circ}$)

If $\Delta ABC \cong \Delta RPQ,$ then which side of $\Delta PQR$ is equal to side $AB$ of $\Delta ABC$?

$ABC$ is an isosceles triangle with $AB = AC$. $BD$ and $CE$ are its two medians. Show that $BD = CE$.

If $\Delta ABC \cong \Delta YZX,$ then in $\Delta XYZ,$ which side is equal to side $AB$?