STEP 1 - RIGHT TRIANGLE x 4: Take one piece of card and fold it in half, then fold it in half again... Image caption, ... use the ruler and pencil to draw a straight line across the bottom corner of ...

Two high school students have proved the Pythagorean theorem in a way that one early 20th-century mathematician thought was impossible: using trigonometry. Calcea Johnson and Ne’Kiya Jackson, both at ...