State the Mid-point Theorem.

State Basic Proportionality Theorem and its converse.

If $△ABC~△DEF$ such that $\angle A=57°$ and $\angle E=73°$ and the measure of $\angle C$  is $k°$, then find the value of $k$

In the following Fig., find $PR$.

In the following fig., $S$ and $T$ are points on the sides $PQ$ and $PR$ respectively of $△PQR$ such that $PT=2 \mathrm{cm}$, $TR=4 \mathrm{cm}$ and $ST$ is parallel to $QR$. Find the ratio of the areas of $△PST$ and $△PQR$.

In fig., $△AHK$ is similar to $△ABC$. If $AK=10 \mathrm{cm},\mathit{ }BC=3.5 \mathrm{cm}$ and $HK=7 \mathrm{cm},$ find $AC$.