Draw an angle of 70°. Make a copy of it using only a straight edge and compasses.

Draw a line AB. Place the centre of the protractor on point A. Coincide AB with the protractor line. Mark C=70. Join AC.

Constructing its copy:

Step 1: Draw another line DE.

Step 2: From O, draw an arc cutting at F and G.

Step 3: Draw arc using the compass with the above arc length, placed at D as centre.

Step 4: Measure GF. Using the same compass length place the point at I and cut the arc.

Step 5: using a ruler draw a line through the cut to get DK. Measure angle KDE using a protractor.