Angle — 170° (Obtuse Angle) — free printable diagram

What is a 170 degree angle?

A 170 degree angle (170°) 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 170° opened between two arms meeting at a vertex.

Measure

170°

Type of angle

Obtuse angle

Supplement (adds to 180°)

10°

Reflex angle on the other side

190°

In radians

17π/18 (≈2.967)

Fraction of a full turn

17/36 of a turn

• A 170° 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° − 170° = 10°.
• Angles round a point add up to 360°, so the reflex angle on the other side of these arms measures 360° − 170° = 190°.
• 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 170°.
• In radians, 170° × π/180 = 17π/18, which is about 2.967.