Angle — 105° (Obtuse Angle) — free printable diagram

What is a 105 degree angle?

A 105 degree angle (105°) is an obtuse angle — it measures more than 90° but less than 180°, so the opening is wider than a square corner but has not yet opened into a straight line. This diagram shows 105° opened between two arms meeting at a vertex.

Measure

105°

Type of angle

Obtuse angle

Supplement (adds to 180°)

75°

Reflex angle on the other side

255°

In radians

7π/12 (≈1.833)

Fraction of a full turn

7/24 of a turn

• A 105° angle is an obtuse angle because it measures more than 90° but less than 180°, so the opening is wider than a square corner but has not yet opened into a straight line.
• Angles on a straight line add up to 180°, so the angle next to this one measures 180° − 105° = 75°.
• Angles round a point add up to 360°, so the reflex angle on the other side of these arms measures 360° − 105° = 255°.
• To measure or draw it, put the centre of the protractor on the vertex where the two arms meet, line one arm up with the 0° mark, and read the scale that starts at 0° on that arm until you reach 105°.
• In radians, 105° × π/180 = 7π/12, which is about 1.833.