Create an equation using the fact that the opposite rays create a straight angle.
m∠FBC=64
Practice makes perfect
Let's begin with recalling that the opposite rays create a straight angle. This means that the sum of the measures of ∠ABD, ∠DBF and ∠FBC is equal to 180. Notice that, as BD bisect ∠ABF, m∠DBF is also 4x+10.
Now we will add the measures of these three angles and use the fact that this sum will be 180.
