Construct $\overline{\mathrm{AB}}$ of length $8 \mathrm{cm}$ and divide it into four equal parts using a ruler and compass only.

Draw an angle measure $40˚$ by using a protractor. Now using compass and a ruler and construct an angle equal to the given angle.

Draw an angle measure $40˚$ by using a protractor. Now using compasses and a ruler only, construct an angle of twice the measure of the given angle.

Draw an angle of measure $40˚$ by using a protractor. Now using compasses and a ruler only, construct an angle of half the measure of the given angle.