PLS HELP I WILL GIVE BRAINLIEST

Answer:
a) correct
b) 70 degrees
Step-by-step explanation:
since in the triangle BXC the sides BX and XC have the same length, they must also have the same angles with the baseline BC.
so, we know, XBC = 55 degrees.
and therefore BCX = 55 degrees.
the sum of all angles in a triangle is always 180 degrees.
so,
BXC = 180 - 55 - 55 = 70 degrees