Construction of the perpendicular bisector of a line segment is not always possible.

Draw a line segment $AB$ of length $5 cm$ with scale and pencil. By folding paper, find the perpendicular bisector of the line segment $AB$. Then measure the two bisected parts with scale.

I drew a line segment $XY$ with scale and pencil. Now we shall draw perpendicular bisector of line segment $XY$ with the help of scale, pencil and pencil compass. If I take a radius, less than half the length of the line segment $XY$ and try to draw an arc with centres $X$ and $Y$, on both sides, what shall I find.

Draw a line segment of length $8 cm$ with scale and pencil. Then draw a perpendicular bisector of this line segment and measure each part.

Draw two circles whose diameters are $5 cm$ and $7 cm$ respectively.

I drew a line segment $XY$ with scale and pencil. Now we shall draw perpendicular bisector of line segment $XY$ with the help of scale, pencil and pencil compass. If I draw arcs with centres $X$ and $Y$ and radius equal to the length more than half the length of the line segments, what shall I observe.

After drawing a line segment $AB$ of length $5 \mathrm{cm}$ with scale and pencil and by folding paper, the measure of each of the bisected parts of line segment $AB$ is 

Draw a line segment $PQ$ of length $6 cm$. With scale and pencil, take line segment $PQ$ as diameter and draw a circle.

With a ruler and compass only, construct the following angle:

$150°$.

In the figure, $\mathrm{AB}=10 \mathrm{cm}$ and $\mathrm{CD}$ is the bisector of line segment $\mathrm{AB}$. If  measure of $\mathrm{MB}=k \mathrm{cm}$, what is the value of $k$.

With the help of scale and pencil a line segment $AB$ of length $8 cm$ is drawn. Divide the line segment $AB$ into four equal parts and measure each part.