<span>Given three equations, x=0</span>
<span>6y-5x=0</span>
<span>x+3y=21</span>
<span>
</span>
<span>The lines cross at:</span>
<span>x=0, y=0</span>
<span>x=0, y=7</span>
<span>x=6, y=5</span>
<span>so base of triangle is the y-axis between 0 and 7</span>
<span>height is x=6</span>
<span>area=6*7/2=20.5</span>
<span>
</span>
<span>volume=1/3*(base area)*height</span>
<span>=1/3*(pi*6^2)*7</span>
<span>=84pi</span>
<span>=263.9</span>