Answer
$m \widehat{FH}=110^{\circ}$
Work Step by Step
In order to compute the arc measurement, we must recall the following points
A) The measure of a semi-circle arc is equal to $180^{\circ}$
B) The measure of a minor arc is equal to the measure of its corresponding central angle.
C) The measure of a major arc is equal to the measure of the related minor arc subtracted from the angle $360^{\circ}$.
In the given question, we can see that $\widehat{FH}$ is a minor arc.
Therefore, we can write $m \widehat{FHJ}=m\widehat{FH}+m\widehat{JH}$
Next, $\widehat{FHJ}$ is a semi-circle.
So, $180^{\circ}=m\widehat{FH}+70^{\circ}$
or, $m \widehat{FH}=110^{\circ}$
