Answer:
m<B=60°
Step-by-step explanation:
an exterior angles equals the sum of its two remote interior angles, so:
m<A+m<B=m<BCG:
3x+4x=10x-45
7x=10x-45
-3x=-45
x=15
to find the measure of <B:
since m<B=4x:
4(15)=60°
so, m<B=60°
