# Math Help - Trig - Prove tan by using similar triangles

1. ## Trig - Prove tan by using similar triangles

Hi, the problem i have here isn't with my trig skills but with my ability to use similar triangles to prove that KZ = tan.

***Could someone please tell me which triangles to use.***

I know from wikipedia, that this is true.

Thank you

2. Originally Posted by mx-
Hi, the problem i have here isn't with my trig skills but with my ability to use similar triangles to prove that KZ = tan.

***Could someone please tell me which triangles to use.***

I know from wikipedia, that this is true.

Thank you
Prove that KZ is equal to the tangent of what angle??

-Dan

3. The above diagram is of a unit circle. Where KZ denotes the length of the segment from the point K to the point Z.

I must prove in general that KZ is the tangent using similar triangles with the Information provided in the first diagram.

It might also help to know that LZ = OJ = cosθ and JZ = OL = sin θ.

Thanks.