By drawing regular polygons as for instance a square will have 4 equal right angles and an equilateral triangle will have 3 equal 60 degree angles.
With a straight edge and a protractor
A protractor is normally used to construct angles.
You cannot, you must use a protractor.
An angle of 65° can not be trisected using a compass and straight edge.
Oh, dude, drawing a 350-degree angle is a piece of cake! Just grab your protractor, start at the zero mark, and swing it around until you hit 350 degrees. It's like drawing a regular angle, but you just keep going a little further. Easy peasy!
It is easy to draw an equilateral triangle without a protractor. That gives a 60 degree angle. It is then simply a matter of bisecting the 60 degree angle, using an unmarked rule and compass, to get a 30 degree angle.
With a straight edge and a protractor
In conjunction with a straight edge and a protractor
it
Use a protractor to measure the angle. Divide that number by 3 and that is the required angle. In general, an angle cannot be trisected using a compass and straight edge.
You can never really be certain about the measure of an angle without using a protractor, or some similar tool. Usually, you can try to "eyeball" it, though. Just remember that a right angle is the same as an angle in a square. It is also a quarter of a whole revolution.
To accurately measure angles using a protractor, place the center of the protractor on the vertex of the angle. Align one side of the angle with the zero line on the protractor. Read the measurement where the other side of the angle intersects the protractor scale.
by using a protractor
One way is to use a protractor. There are others
By using a protractor or using trigonometry
By using a protractor we can measure an angle
A protractor is normally used to construct angles.