A map is drawn on a coordinate plane. Each unit represents 10 miles. Terri drives from her home at point G to her friend’s home at point H, following the route shown on the graph at the top of the next column. How long is the distance between the two points?

Could somebody me with this radical simplification?

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.

Find the dimensions of the circle. area = 64π in.² r= in.