The Burj Khalifa located in Dubai is the tallest building in the world at 2,717 feet, which is 0.515 miles. The radius of the earth is 3,959 miles. If you stood on top of the Burj Khalifa, how far to the horizon could
you see?

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.