A section of a roller coaster track forms a parallelogram ABCD.
If m∠ABC = 72°, what is m∠DAB?
A 144°
B 108°
C 72°
D 216°
Since opposite angles in a parallelogram are congruent, we know that m∠ABC = m∠CDA = 72°.
Therefore, the other two angles in triangle ABD must add up to 180° - 72° = 108°.
Since AB and CD are parallel, we also know that m∠DAB and m∠CDA are corresponding angles and therefore congruent.
So, m∠DAB = m∠CDA = 72°.
Therefore, the answer is C) 72°.