Since the sides are parallel, angles B and C add to 180 degrees I(supplementary)
C= 3B C+B = 180 Substitute 3B + B = 180 4B = 180 B = 45 degrees
Since the sides are parallel, angles B and C add to 180 degrees I(supplementary)
C= 3B C+B = 180 Substitute 3B + B = 180 4B = 180 B = 45 degrees