Straight line angles and angles around a point

Maths

Angles on a straight line sum to 180 degrees.

Angles around a point sum to 180 degrees.

If a straight line contains 2 angles, one of which is 54 degrees, what is the size of the other angle?

If a + b = 180 degrees, then 2a + 2b = 360

Vertically opposite angles are never equal.

The total sum of the interior angles of two triangles would be equal to...

If I have a regular pentagon, how many triangles from one distinct point internally can I create?

If I have a regular pentagon, what would the total interior angles sum to?

If I have a regular octagon, how many triangles from one distinct point internally can I create?

If I have a regular octagon, what would the total interior angles sum to?