# Hi All! Need help with this question please! Thank you!

• Sep 19th 2013, 03:43 AM
mynameiscosine
Hi All! Need help with this question please! Thank you!
Hi all! Thank you for taking the time to help me!

I can't seems to start this question. Hope someone can guide me in the right direction, thanks!

Attached is a picture of the diagram.

The question is
Given AD is tangent to the circle at A.
BCD is a straight line that intersects the tangent at D.
DHK is the angle bisector of Angle ADC and it cuts AC at H and AB at K.

a) show that HD * BD = KD * AD
* meaning multiply/product.
b) show that triangle AHK is an isosceles triangle.

Thank you!
• Sep 19th 2013, 02:23 PM
BobP
Re: Hi All! Need help with this question please! Thank you!
The starting point is to see that angle CAD is equal to the angle CBA.
(It's a basic angle property of a circle.)
After that it's a routine similar triangles job.
• Sep 19th 2013, 05:44 PM
mynameiscosine
Re: Hi All! Need help with this question please! Thank you!
Ohhh. I got it now. Thank you so much! I didn't notice it. Thank you!
• Sep 20th 2013, 07:29 AM
johng
Re: Hi All! Need help with this question please! Thank you!
Hi,
I was busy drawing the attachment and didn't see that BobP had answered your question. Here's my solution anyway:

Attachment 29209