Answer:
X = 13.13 feet
Step-by-step explanation:
Let the distance between Lila and Mark be x.
Let the distance between Avery and lila be A= 20
Let the distance between Avery and Mark be B= 30
Angle x = 200-180=20°
To solve this question we will use the cosine formula which is
X² = A²+ B² -2ABcosx
X²= 20² + 30² -2(20)(30)cos20
X²=1300-1127.6
X²= 172.4
X= 13.13