+92 Hello Cdortch.
SOLUTION:
Do you know Heron's Formula? It will greatly benefit you in this problem.
Heron's formula states that the area of a triangle is equal to the square root of the semiperimeter times... well, I'll just write it out. $s$ is semiperimeter. \[A=\sqrt{s(s-a)(s-b)(s-c).}\] Now, when we plug in the values, we find that the area of a smaller triangle is $\sqrt{\dfrac{9}{2}(\dfrac{9}{2}-1)(\dfrac{9}{2}-4){(\dfrac{9}{2}-4)}}$. We then multiply this by 2.
Putting the above equation into a calculator, we get $\frac{3\sqrt{7}}{2}$.
Hope this helped! 
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