One hypothesis about the shape of the universe is that the universe is in the space of Euclidean geometry and flat. In Euclidean geometry, it is assumed that straight lines extend everywhere, planes ...

Understanding different types of angles and that angles in a triangle sum to 180° can be helpful when classifying a triangle. Recognising line symmetry and rotational symmetry will also help. Look for ...

We know all four shapes are the same before and after, but we assumed that the large right triangle also stayed the same size and shape. This assumption was our error! It turns out that the “before” ...

The three angles in a triangle add up to \(180^\circ\). If two of the angles are known then the third can be calculated by following these steps: Add the two known angles together. Subtract the total ...