Answer:
Option C
Step-by-step explanation:
we know that
The measurement of the <u>exterior angle</u> is the semi-difference of the arcs it comprises
so
we have
substitute
Rewrite
Step one:
12h-7=7h+18
12h-7h-7+7=7h-7h+18+7 Additive inverse
5h=25
Step two:
5h=25
5/5h=25/5 Multiplicative inverse
h=5