A doctor observes a graph that shows the electrical activity (in volts) of the heart of a patient over a period of time (in seconds). Each local maximum of 0.004 volts corresponds to one heartbeat. The doctor needs to calculate the heart rate of the patient in beats per minute. What is the heart rate of this patient? _Beats per minute

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.