Measure of each exterior angle of an equilateral triangle is $\ldots \ldots \ldots$ (in $^{\circ}$)

$S$ is any point in the interior of $\triangle PQR$. Show that $SQ + SR < PQ + PR$.

In $\Delta ABC$,$AD$ is a median. If $\operatorname{ar}(ADB) = 53 \, cm^2$,then find $\operatorname{ar}(ABC)$ in $cm^2$.

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

In $\Delta ABC$, $\angle B = \angle C$, $AB = 5 \text{ cm}$, and $BC = 8 \text{ cm}$. Then, the perimeter of $\Delta ABC$ is: (in $\text{ cm}$)

Write the measures of its sides in ascending order in each of the following triangles:
$(1)$ In $\Delta ABC$,$\angle B = 70^{\circ}$ and $\angle C = 20^{\circ}$.