Drawing a correct angle in the 11th century

[ERELCE]

I have to reproduce a drawing with old technics.
But how they did draw a correct angle in the 11th centurie?
I have to draw angles of 13, 7, 53 .... degrees.

[philip]

Maybe it is not possible to draw correctly angles of 7, 13, 53 degrees without a protractor.

[AlanAnderson]

You need a protector to draw a correct angle, I don't think it is possible to draw exact 7, 13 and 53 angles.

[leesajohnson]

I'm not sure about but it might be possible that they draw the correct angel with the help of shadow, as earlier people see the time when there is no clock for watching the time.