Angles
⭐ MasteredAngles measure turns and are measured in degrees. A right angle is 90°, a straight line is 180° and a full turn is 360°.
A triangle's angles always add up to 180°.
All about Angles
An angle is formed where two lines or rays meet. Angles are measured in degrees, using a protractor. A full turn is 360°, a half turn (a straight line) is 180° and a quarter turn is a right angle of 90°.
Angles are named by their size. An acute angle is less than 90°, an obtuse angle is between 90° and 180°, and a reflex angle is more than 180°. Angles appear everywhere, from the corner of a book to the hands of a clock.
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Real-life uses of Angles
- Measuring how far a skateboard ramp is tilted
- Setting the corners of a picture frame to right angles
- Aiming a ball at a target
Frequently asked questions about Angles
How many degrees are in a triangle?
The three angles inside any triangle always add up to 180°.
What is a right angle?
An angle of exactly 90 degrees, which is shown with a small square in the corner.
How do you use a protractor?
Line up the centre of the protractor with the angle's vertex and one arm with the zero line, then read the scale where the other arm crosses it.