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Angles

Identify right angles, acute and obtuse angles

What is an Angle?

An angle is formed where two lines meet at a point. We measure angles in degrees (°). A full turn is 360°. A half turn is 180°. A quarter turn is 90°.
Example

Types of Angles

Right angle: exactly 90° (like the corner of a book) — marked with a small square. Acute angle: less than 90° (small and sharp). Obtuse angle: more than 90° but less than 180° (wide and open). Straight angle: exactly 180° (a straight line).

Finding Angles Around Us

Right angles are everywhere: corners of doors, windows, and books. The hands of a clock form angles — at 3 o'clock they make a right angle! At 6 o'clock they make a straight angle.
Note

Remember

Right angle = 90° (square corner). Acute angle < 90° (sharp). Obtuse angle > 90° (wide). Always look at where the two lines meet to identify the angle.

Key Vocabulary

AngleThe space between two lines that meet at a point
DegreeThe unit used to measure angles (°)
Right angleAn angle of exactly 90°
Acute angleAn angle less than 90°
Obtuse angleAn angle between 90° and 180°

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