Concept:A protractor is the instrument used to measure the angle between two lines that meet at a point.
Explanation:A protractor is a semicircular measuring tool graduated from
0∘ to
180∘.
To measure an angle, place the centre of the protractor exactly on the point where the two lines meet.
Align one line with the zero mark, then read the scale where the second line crosses the protractor.
The other instruments have different uses.
A pair of compasses is used to draw circles and arcs.
A set-square is used to draw straight lines and to check right angles (
90∘).
A pair of dividers is used to measure and compare lengths, not angles.
Therefore, the protractor is the only tool among the options that measures angles directly.
Answer:C. protractor