Answer:
SAS theorem
Step-by-step explanation:
If 
and m∠ECD = m∠BCA, then the triangles are similar by the SAS theorem.
So, and m∠ECD = m∠BCA because vertical angles are congruent
Therefore ΔECD is similar to ΔBCA by SAS theorem
Two angles are supplementary when they <span>add up to 180 degrees </span>⇒
m∠1 + m∠2 = 180°
4y + 7 + 9y + 4 = 180
13y + 11 = 180
13y = 180 - 11
13y = 169
y = 169/13
y = 13
m∠2 = 9y + 4 = 9 * 13 + 4 = 121°
Mark me as brainliest! :)
1/6 * 3/2 = 1/4
