Step-by-step explanation:
step 1. there are 3 right triangles!
step 2. 8/6 = 6/x (definition of right triangle with an altitude)
step 3. 8x = 36 (cross multitude)
step 4. x = 9/2 (divide both sides by 8)
step 5. 6^2 + x^2 = y^2 (pythagorean theorem)
step 6. 6^2 + (9/2)^2 = y^2
step 7. 144/4 + 81/4 = y^2
step 8. 225/4 =y^2
step 9. y = 15/2 = 7.5.
