To find the area of the triangle
⇒ must know the area of the triangle's formula
⇒ [tex]\frac{1}{2} *base*height[/tex]
Let's look at the information given:
Let's solve:
[tex]Area=\frac{1}{2} *base*height=\frac{1}{2} *\frac{61}{4} *18 = 137.55in^2[/tex]
Thus the area is 137.55 square inches
Hope that helps!