Answer:
113.8°
Step-by-step explanation:
You want to know the measure of angle J in ∆HIJ with h=260 in, i=380 in, j=540 in.
Law of Cosines
The law of cosines tells you ...
j² = h² +i² -2hi·cos(J)
J = arccos((h² +i² -j²)/(2hi)) . . . . . . solve for angle J
J = arccos((260² +380² -540²)/(2·260·380)) = arccos(-79600/197600)
J ≈ 113.755° ≈ 113.8°
The measure of ∠J is about 113.8°.
