i just carnt get the trig answers.....

• Jun 2nd 2008, 01:32 PM
Steven H
i just carnt get the trig answers.....

a. Find the area of a triangle in which A=60degrees, b=182.5cm,c=160cm .

b. Calculate the area of a regular fifteen-sided figure inscribed in a circle of radius 10cm.

plz help thank you for any help.
• Jun 2nd 2008, 01:43 PM
Mathstud28
Quote:

Originally Posted by Steven H
a. Find the area of a triangle in which A=60degrees, b=182.5cm,c=160cm .

b. Calculate the area of a regular fifteen-sided figure inscribed in a circle of radius 10cm.

plz help thank you for any help.

For the first one you can use trigonometry to find the height of your triangle and proceed to find area the normal way $A_{triangle}=\frac{1}{2}bh$

For the second one do you know the formula

$A_{\text{regular n-gon}}=\frac{1}{2}\alpha{p}$
where p is the perimiter and alpha is the apothem?
• Jun 2nd 2008, 01:51 PM
Steven H
Quote:

Originally Posted by Mathstud28
For the first one you can use trigonometry to find the height of your triangle and proceed to find area the normal way $A_{triangle}=\frac{1}{2}bh$

For the second one do you know the formula

$A_{\text{regular n-gon}}=\frac{1}{2}\alpha{p}$
where p is the perimiter and alpha is the apothem?

im not sure how to do any of it to be truth full especially the second equation any other pointers i would be greatful for any other tips.
thank you very much.
• Jun 2nd 2008, 01:54 PM
Mathstud28
Quote:

Originally Posted by Steven H
im not sure how to do any of it to be truth full especially the second equation any other pointers i would be greatful for any other tips.
thank you very much.

My advice for the first one would be to draw the picture, from there I think you will be able to see what you need to do,

For the second one the apothem is more of a visual concept, so look here and see if you can glean how to do it from that. If not post back

Apothem - Wikipedia, the free encyclopedia
• Jun 2nd 2008, 02:00 PM
Steven H
Quote:

Originally Posted by Mathstud28
My advice for the first one would be to draw the picture, from there I think you will be able to see what you need to do,

For the second one the apothem is more of a visual concept, so look here and see if you can glean how to do it from that. If not post back

Apothem - Wikipedia, the free encyclopedia

thanks for your tips i think the scary thing is the 15 sides it seems a lot of sides.