testing header
Math Goodies is a free math help portal for students, teachers, and parents.
Free Math
Interactive Math Goodies Software

Buy Math Goodies Software
testing left nav
Math Forums @ Math Goodies
Math Forums @ Math Goodies
Home | Profile | Active Topics | Members | Search | FAQ
 All Forums
 Homework Help Forums
 Geometry and Trigonometry
 OK with tan but ...

Note: You must be registered in order to post a reply.

Format Mode:
Format: BoldItalicizedUnderlineStrikethrough Align LeftCenteredAlign Right Horizontal Rule Insert HyperlinkInsert EmailInsert Image Insert CodeInsert QuoteInsert List Insert Special Characters Insert Smilie
* Forum Code is ON

Math Symbols
Squared [squared] Cubed [cubed] Square Root [sqrt] Cube Root [cbrt] Pi [pi]
Alpha [alpha] Beta [beta] Gamma [gamma] Theta [theta] Angle [angle]
Degrees [degrees] Times [times] Divide [divide] Less Than or Equal To [less-than] Greater Than or Equal To [greater-than]
Plus Minus [plus-minus] Integral [integral] Sum [sum] Sub 1 [sub-1] Sub 2 [sub-2]
Element Of [element-of] Union [union] Intersect [intersect] Subset [subset] Empty Set [empty-set]

  Check here to subscribe to this topic.

T O P I C    R E V I E W
daimath Posted - 07/13/2013 : 02:28:37
Start with a triangle ABC with angle ACB =
Then length AB = tan x length AC

So far so good.

But assume that C is at the center of a circle with a radius of AC and that line AD is drawn so that D is at the intersection of line BC and the circumference of the circle.

How does one calculate the length of AD by reference to the length of AC and the angle ?

(It would have been nice to have been able to add a diagram to illustrate the problem but I can't see how to do that.)
3   L A T E S T    R E P L I E S    (Newest First)
daimath Posted - 07/14/2013 : 06:23:22
Thanks Ultraglide. Your answer is much appreciated.
Ultraglide Posted - 07/13/2013 : 23:59:59
I will make one assumption - the point D is not on the same side of AB as the centre C. Note that DC is a radius and is equal to AC and is the angle between DC and AC. Using the Law of Cosines, cos = (DC+AC-AD)/(2DC.AC). Rearranging, AD = DC + AC - 2DC.ACcos. Since AC=DC. AD = 2AC- 2ACcos which gives:

AD = AC(2(1-cos)
daimath Posted - 07/13/2013 : 20:17:11
Sorry! I should have made it clear that triangle ABC is a right angled triangle with the lines AB and AC subtending the right angle.

Math Forums @ Math Goodies © 2000-2004 Snitz Communications Go To Top Of Page
This page was generated in 0.04 seconds. Snitz Forums 2000
testing footer
About Us | Contact Us | Advertise with Us | Facebook | Blog | Recommend This Page

Copyright © 1998-2014 Mrs. Glosser's Math Goodies. All Rights Reserved.

A Hotchalk/Glam Partner Site - Last Modified 18 Dec 2014