question_answer 33)

Draw an angle of \[{{40}^{o}}\]. Copy its supplementary angle.

Answer:

                To draw an angle of measure \[{{40}^{o}}\], we use the following steps:             Step I   Draw a line I and mark three points D, A and B on it. Place the centre of the protractor at A and the zero edge along \[{{l}_{1}}\]. Step II Start with zero near B, mark point C at \[{{40}^{o}}\]. Step III Join AC. Then, \[{{l}_{1}}\]is an angle of measure \[{{40}^{o}}\]. We know that, the sum of two supplementary angles is \[{{180}^{o}}\] and I is a straight line. So, \[{{l}_{2}}\]i.e. \[S\to \] is the supplementary angle of\[Y\to \] Now, to draw the supplementary of an angle \[{{40}^{o}}\], we use the following steps of construction :         Step IV To copy \[M\to \]draw a line I and choose a point P on it. Step V   Place the compasses at A and draw an arc to cut the rays of DAC at P and Q, respectively. Step VI Use the same compasses setting to draw an arc with P as centre, which cuts the line I at M. Step VII Set your compasses to the length PQ. Then, without disturbing the setting of compasses. Place the compasses pointer at M and draw the arc which cuts the previous arc (drawn in Step VI at N). Step VII Join MN. Then, we get \[E\to \] which is the copy of \[T\to \]i.e. supplementary angle of \[{{40}^{o}}\].