Question

how to draw 70 degree angle?

Answer 1

First draw the four quadrants with  X axis and Y axis.  Or  draw  AB horizontally.  Draw a perpendicular line CD  in the middle of AB intersecting it at O.

There is a procedure for trisecting an angle.  Trisect angle AOD (90 deg).  let angle AOE = 30 deg.  

Thus angle  BOE is  180+30 = 210 deg.

Use the procedure for trisecting this angle BOE.   You will get  70 deg. from BO.  

okay?  
This is a good procedure.  Check up the procedure for trisecting an angle.