Can you solve it? Here’s (not) looking at Euclid

A trio of triangle teasers

The ancient Greek geometer Euclid presented a list of five axioms he held to be self-evidently true. They are (or are equivalent to):

You can draw a line between any two points.

You can extend lines indefinitely.

You can draw a circle at any point with any radius.

All right angles are equal.

All triangles have internal angles that add up to 180 degrees.