Evaluate each expression for the given value of each variable.

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.

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

The table below shows the angle measurements for triangle abc and triangle xyz. if triangle abc is similar to triangle xyz, what does angle z equal, in degrees?