Question

Find the value of y

Answer 1

Let's call the side BD Z and the angle ACD X and the angle CDA W, you can observe that those triangles have the same angles : X,W and 90. That implies:

`(z)/(6) = (5)/(z) \\ \\ z {}^(2) = 30 \\ \\ y {}^(2) = z {}^(2) + 5 {}^(2) \\ \\ y = √(30 + 25) \\ \\ y = √(55)`