Exterior Angle Calculator

Work out exterior angle instantly with clear inputs, formula shown and shareable results.

About Exterior Angle Calculator

The exterior angle theorem states that an exterior angle of a triangle equals the sum of the two non-adjacent (remote) interior angles, and it forms a linear pair with the interior angle beside it.

Formula

Exterior angle theorem

exterior = remote interior 1 + remote interior 2 = 180° − adjacent interior

Worked example

With the default values below, Exterior Angle Calculator returns Exterior angle of 110.0000. Change any input above and every figure here is recalculated in your browser.

Inputs used

First remote interior angleaccepts 0–180 °: 50 °
Second remote interior angleaccepts 0–180 °: 60 °

Results

Exterior angle: 110.0000 °
Adjacent interior angle: 70.0000 °
Sum of remote interior angles: 110.0000 °
Linear pair check: Exterior 110° + adjacent interior 70° = 180°

Step by step

1Values used
2Exterior angle theorem
3Exterior angle= 110.0000 °
4Adjacent interior angle= 70.0000 °
5Sum of remote interior angles= 110.0000 °
6Linear pair check= Exterior 110° + adjacent interior 70° = 180°

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Do exterior angles of a polygon also sum to 360°?

Yes. Taking one exterior angle at each vertex of any convex polygon, the total is always 360°.

Can an exterior angle be smaller than an interior angle?

Yes. If the adjacent interior angle is obtuse, its exterior angle is acute and smaller.