A set-square.
Protractor
The semi-circle ruler is commonly known as a protractor. A protractor is a geometric tool used to measure and draw angles. It typically has a half-circle shape with degree markings along the curved edge.
A protractor measures the degree of angles and circles.
A protractor is normally used to construct angles.
A circle. ;-)
Protractor .
It is called a protractor.
That tool is called a protractor.
Protractor
A set-square.
It is called a protractor.
A protractor measures the angle between two lines meeting at a point called a vertex. The angle measurement is in degrees.
It is called a protractor.
Protractor
The instrument for measuring the angles of a triangle is called a protractor.
The instrument used to measure the angle between two lines is called a protractor. A protractor typically consists of a semicircular or circular tool with markings for degrees. To measure the angle, the protractor is placed along one line with the center point at the intersection of the two lines, and the angle is read where the second line crosses the protractor.