Triangle C-B-A, right angled at B with the length of its height C-B as b, base B-A as a, and the hypotenuse A-C as c, has a perpendicular line B-D from vertex B to its hypotenuse A-C forming two right triangles B-D-C with its base as D-C of length e and right triangle C-D-B with its base as D-A of length d.
Thomas is attempting to prove the Pythagorean Theorem using similar triangles. Which of the following could be Thomas's first ratio that he sets up?
A.
B.
C.
D.