Supplementary angles add up to 180 degrees. Given that <D and <E are supplementary angles, we can set up the equation:
\[ m<D + m<E = 180 \]
Substituting the expressions for the angles, we have:
\[ (4x + 8) + (x + 17) = 180 \]
Now, combine like terms:
\[ 4x + x + 8 + 17 = 180 \] \[ 5x + 25 = 180 \]
Next, isolate \(x\) by subtracting 25 from both sides:
\[ 5x = 155 \]
Now, divide by 5:
\[ x = 31 \]
Now, we can find the measure of angle <D:
\[ m<D = 4x + 8 = 4(31) + 8 = 124 + 8 = 132 \]
Since <F is a vertical angle to <D, the measure of <F is equal to the measure of <D.
Therefore,
\[ m<F = 132 \]
Thus, the measure of <F is 132 degrees.