For a right-angled triangle, follow these steps to calculate the length of a side, x, when another side and an angle Ɵ is given: Label the two sides that contain information in the diagram with ...

BURKARD POLSTER, MARTY ROSS, One-Glance (ish) Proofs of Pythagoras′ Theorem for 60-Degree and 120-Degree Triangles, Mathematics Magazine, Vol. 89, No. 1 (February 2016), pp. 47-54 ...