Answer:
Part a) The measure of angle F is 73°
Part b) The value of x is 17
Step-by-step explanation:
step 1
Find the measure of angle F
we know that
<F+107°=180° -----> by supplementary angles
so
<F=180°-107°=73°
step 2
Find the value of x
we know that
The sum of the interior angles in a triangle must be equal to 180 degrees
so
<E+<D+<F=180°
substitute the values
(3x+5)°+51°+73°=180°
solve for x
3x=180°-129°
x=51°/3=17