The sum of interior angles in a triangle is 180°. To prove \(a + b + c = 180^\circ\), firstly draw a line parallel to one side of the triangle. \(d = b\) (alternate angles are equal ...

The angle between the north line and the flight ... You need to use a compass as well as a pencil and ruler to find the midpoint of a line segment. What is the locus of a point that's further ...