here ZLS defines a line segment with end points Z and S.
so it represents line segment ZS
So option B is correct
X = 60°
To work this out, you would do 50°+70° to get 120°. You would then subtract this from 180° (the total for any triangle) to get the final answer of 60°.
This is the answer, hope this helps you
2bc
=2(2)(3)
=4(3)
=12
2bc = 12
b=2
c=3