Answer:
x is 37.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.
x = 37
Step-by-step explanation:
Interior angles of a square is 90 each.
∠JKL = 90°
Given ∠JKL = 3x - 21
Therefore, 3x - 21 = 90
3x = 90 + 21
3x = 111
