You can split a rectangle into 2 right-angled triangles. Image caption, STEP 2: Use the compass to draw a circle. Put a dot where the compass rested and use the ruler to draw a horizontal line ...

We are now going to extend trigonometry beyond right angled triangles and use it to solve problems involving any triangle.

What began as a bonus question in a high school math contest has resulted in ... the relationship between the three sides of ...