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

1. ## 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!

2. ## 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.

3. ## 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!

4. ## 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: