Calculate the value of $x$ in the figure given. (Write the answer without degree symbol)

 

In the given figure, $AB\parallel CD$. If $\angle CED=x°$, then find the value of $x$.

If the missing angle is of the value $\mathrm{x}°$, then find the value of $\mathrm{x}$.

In the figure given alongside, $AB\parallel CD, EF\parallel BC, \angle BAC={60}^{\mathrm{o}}$ and $\angle DHF={50}^{\mathrm{o}}$. Find $\angle GCH$ and $\angle AGH.$

If the sides of a triangle are produced in order, prove that the sum of the exterior angles so formed is equal to four right angles.

In the adjoining figure, show that $\angle \mathrm{A}+\angle \mathrm{B}+\angle \mathrm{C}+\angle \mathrm{D}+\angle \mathrm{E}+\angle F=360°$.