To determine the value of \( FH \), we need to remember that in a rectangle, opposite sides are equal in length. Therefore, since \( FGHI \) is a rectangle, it follows that:
\[ FH = GI \]
From your question, we have:
\[ FH = 16a + 14 \] \[ GI = 8a + 86 \]
Setting these two expressions equal to each other gives us:
\[ 16a + 14 = 8a + 86 \]
Now we'll solve for \( a \):
- Subtract \( 8a \) from both sides:
\[ 16a - 8a + 14 = 86 \] \[ 8a + 14 = 86 \]
- Subtract 14 from both sides:
\[ 8a = 86 - 14 \] \[ 8a = 72 \]
- Divide both sides by 8:
\[ a = \frac{72}{8} = 9 \]
Now, we can substitute \( a = 9 \) back into the expression for \( FH \):
\[ FH = 16a + 14 \] \[ FH = 16(9) + 14 \] \[ FH = 144 + 14 \] \[ FH = 158 \]
Thus, the value of \( FH \) is:
\[ \boxed{158} \]