The double angle formula for the sine is

The right hand side is exactly your expression, where 
So, rewriting the expression from right to left, we have

Answer:
yes, because they have the same angle measures.
(congruent triangles have equal angles)
Step-by-step explanation:
Step-by-step explanation:
<h3>Part A</h3>
<u>Angle measures:</u>
- a = x = z = 51° (as vertical angles and corresponding angles)
- b = d = y = w = 180° - 51° = 129° (as supplementary angles and corresponding angles)
<h3>Part B</h3>
Supplementary angles for a linear pair and sum to 180°.
<u>Examples are:</u>
- a and b or
- a and d or
- x and y etc.
The equation equivalent to this formula would be D)b1=2A-b2