Angles in a triangle

★★★Not the suggested order

The three angles of a triangle always add to 180°.

Fraction Island · Learn first

Example

A triangle has angles 44° and 22°. What is the third angle?

44° + 22° + = 180°

Answer: 114 °

Steps in this unit · Angles

1 2 3 4

← Angles on a line Angles in a quadrilateral →

Angles · Shapes & Geometry

Sort acute, right and obtuse angles; find missing angles on a line, in a triangle, in a quadrilateral.

The three angles of a triangle always add to 180°.

This is step 3 of unit 6, “Angles”, in Stage 5: Big numbers, fraction and decimal sums, angles (ages 11). A round has 10 problems; 90% or better earns three stars. Everything is free with no sign-up, and your stars and XP are saved on this device.