# [SOLVED] Area of a Triangle?

• October 30th 2008, 04:02 PM
fabxx
[SOLVED] Area of a Triangle?
In the xy-plane, what is the area of a triangle whose vertices are http://www.collegeboard.com/prod_ima...2c/prac22j.gif,
http://www.collegeboard.com/prod_ima...2c/prac22k.gif, and http://www.collegeboard.com/prod_ima...2c/prac22h.gif?
(A) 3.59 (B) 5.67 (C) 7.91 (D) 11.18 (E) 11.34
• October 30th 2008, 05:10 PM
skeeter
$A = \frac{1}{2}bh = \frac{1}{2}(5 - \sqrt{2})(\sqrt{10})$
• October 30th 2008, 05:22 PM
fabxx
Quote:

Originally Posted by skeeter
$A = \frac{1}{2}bh = \frac{1}{2}(5 - \sqrt{2})(\sqrt{10})$

how did you get b as 5-sqrt2?

Thanks again!!
• October 30th 2008, 05:26 PM
skeeter
the points on the x-axis are $(5,0)$ and $(\sqrt{2},0)$

the distance between those two values is $5 - \sqrt{2}$