Drawing angles with a protractor, step by step
Setting a protractor is harder than reading one.
The question
Draw angle ABC = 25°, with C above BA.
Draw angle ABC = 25°, with C above BA.
Draw an angle
readvsset
origin on B+zero on BA
25°not155°
mark→draw→arc
- Setting a protractor is harder than reading one, because you choose where to start counting rather than being told.
- Origin on B, zero line along the given ray BA. Both at once — if either is off, every degree after it is off with it.
- Count from the zero that sits on BA. The other scale would give 155° instead, which is the mistake this question is really testing.
- Mark the degree, take the protractor away, and draw BC through the mark with a straightedge. Then mark the angle with a small arc so the size you meant is on the page.
How it works.
- 01
Setting a protractor is harder than reading one, because you choose where to start counting rather than being told.
- 02
Origin on B, zero line along the given ray BA. Both at once — if either is off, every degree after it is off with it.
- 03
Count from the zero that sits on BA. The other scale would give 155° instead, which is the mistake this question is really testing.
- 04
Mark the degree, take the protractor away, and draw BC through the mark with a straightedge. Then mark the angle with a small arc so the size you meant is on the page.