A room in the shape of a triangle has sides of length 7 yd, 8 yd, and 11 yd. If carpeting costs $17.50 a square yard and padding costs $3.25 a square yard, how much to the nearest dollar will it cost to carpet the room, assuming that there is no waste?

Question

anonymous · Answer

i think i figured this out at $579.77 0r $580 :)

anonymous · Answer

|dw:1321767001561:dw|

anonymous · Answer

i got $581.00. soo idk.. lol

anonymous · Answer

Using heron's forumula for calculating the height
s=(a+b+c)/2
h=2/c *sqrt(s(s-a)(s-b)(s-c))

Plugging in a=8, b=7, c=11, I get h=5.08

Then the area is 5.08 * 11 = 55.86

Multiply that by the total cost of materials:
cost= 55.86*(3.25+17.50)

I get $1159.03

anonymous · Answer

oops, and divide by 2 that's 579.52

anonymous · Answer

$$A=1/2\times b \times h$$
$$A=(.5) \times (7) \times (8) $$
= 28SQ. Feet 

$17.50 x 28= $490 
$3.25 x 28+ $91 
$490+91=$581.00

anonymous · Answer

emistre: 
7 and 8 are not the base and height of the triangle.  It's not a right triangle.

anonymous · Answer

ok

anonymous · Answer

The answer was 580 as we were to round up. Thank you for the assistance!