Angles in a triangle

This is similar to angles in a quadrilateral, but remember, the angles always add up to 180 degrees, not 360.

Let's try this question:

Find the angle labelled x.

Ok, so first we add the two angles we know together:

75 + 50 = 125 degrees

And now we subtract this from 180 degrees:

180 - 125 = 55 degrees

So now we know that angle x = 55 degrees.

Test your knowledge on this with our short quiz: