protractor

/proh-trak-ter, pruh-/US // proʊˈtræk tər, prə- //UK // (prəˈtræktə) //

量角器,量具,半圆仪

Definitions

n.名词 noun

1
- : a person or thing that protracts.
- : an instrument having a graduated arc for plotting or measuring angles.
- : Anatomy. a muscle that causes a part to protrude.

Then, if we have a protractor, we may apply it to the lines and see how many degrees of angle they contain.
The student should have and use a protractor, such as is furnished with this book, for the numerous exercises which are to follow.
Rule another line along the same edge of the board as before and with a protractor measure the angle between these lines.
At that point find, by means of a protractor, the angle a projection of the chord makes with the face of the beam.
No witness could tell more truth than the compass and protractor of Mr. Smith which were free from prejudice and partiality.