Saturday

January 31, 2015

January 31, 2015

Posted by **Mary** on Sunday, May 22, 2011 at 3:18pm.

I know the perimeter is 40.

Now I need the area.

- Geometry -
**Reiny**, Sunday, May 22, 2011 at 4:30pmdraw the trap ABCD where AD=10,DC = 7, BC=17 and BA = 6

Draw AE parallel to DC, then AE=7 and BE = 7

We now have a parallelogram and a triangle.

Let's find angle AEB which is also angle C , call it Ø

by cosine law in triangle ABE

6^2 = 7^2 + 7^2 - 2(7)(7)cosØ

cosØ = .632653

Ø = 50.75386°

area = triangle + parallelogram

= (1/2)(7)(7)sin 50.75386 + (10)(7)sin50.75386

= 73.184

**Answer this Question**

**Related Questions**

geometry - in a triangle the middle length side is 3 more than the shortest side...

geometry problems (algebra) - the lengths of the triangle are consecutive odd ...

calculus help lttle question - find the area of the regin bounded by the graphs ...

geometry - The shortest side of two polygons have lenghts in the ratio 2:5.The ...

Geometry Inscribed Angles Multiple Choice - Find the measure of angle BAC. {...

algebra 1 - The perimeter of a triange with sides a,b,and c is 24 cm. Side a is ...

GEOMETRY HELPPPPP MEEEE PLEASSEEEEE!!! - Find the lengths of the diagonals of ...

math grade 6 - give the demention of the rectangle with an area of 100 square ...

geometry - ok i have 2 problems and id appreciate it if someone can help :) 1. ...

Math - Find the Maximum area for the given perimeter of a rectangle. State the ...