Answer with explanation:
In Δ K J M, ∠KJM is an acute angle.
So, 0° < ∠KJM < 90°
⇒ 0° < (3 x +18)° < 90°
Adding, -18 on both sides of inequality
⇒ 0 -18 < 3 x +18 -18 < 90-18
⇒ -18 < 3 x < 72
Dividing by , 3 to whole Inequality
⇒ -6 < x < 24
Option B , is most Appropriate.
⇒B. -6 < x < 11