ElectricPavlov

The triangle with the ? in it has a 90 degree angle , a ? angle and a 15 degree angle in it (the upper 90 angle of the square has 60 degrees taken away from it, leaving the remainder split between two small angles on either side of the 60)..

    Does this help?

Heck yah !    ( but I got 44.803)

I am sure you know how to find the area of a triangle ....right? This figure is TWO triangles....add them together to find the total area.....c'mon.....don't make this more difficult than it really is....

To find AREA      I'd go two triangles .... BOTH with base 7     one with h = 2   one with h = 2

Careful....    Pythagorean Theorem only works for RIGT triangles !

...or break it in to two triangles     area of triangle = 1/2 base x height

Exactly!!! Kudos !

You are getting there....but what happens when you square a NEGATIVE number   (1-4)^2 = (-3)^2       Hmmmmm....did you forget?

The BASE is 4   obviously ....right?

Distance between two points ( I KNOW you have seen this in recent days)

d^2 = (x1-x2)^2 + (y1-y2)^2     (this is just a Pythag Theorem re-written)

So using points    4,1    and  2,4           d^2 = (4-2)^2 + (1-4)^2   = 13     right?  

      so d = sqrt 13    the length of ONE leg....there are TWO of these legs 

               so  2 sqrt 13    PLUS the base (4) = perimeter = 11.21 units           

  Cool now?   You can do this.......

How many moles of ammonia are there?    20

2 moles of ammonia come from ONE mole of N2       How many moles of N2 is that?   What did you get?

THEN use    PV = n RT to find   V for the nitrogen....  Let me know waht you find....G'Luck !