Write the standard form of the equation of the circle with center (3, 9) that passes through the
point (-2, 4).

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

What is the number 321,000,000 in scientific notation? also what is the number? ?

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.