To find the value of a, subtract the y-coordinate of the vertex from the y-coordinate of the point on the parabola that is 1 unit to the right of the vertex. y = a (x-2)^2 + -2

- Find the value of a for the parabola

- Write the equation of the parabola

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.