9514 1404 393
Answer:
4.3 in
Explanation:
The Law of Cosines is applicable when you have two sides and the angle between them. The third side satisfies ...
f² = d² + e² -2de·cos(F)
f² = 6.4² + 7.8² -2·6.4·7.8·cos(33°) ≈ 18.0671
f ≈ √18.0671 ≈ 4.2505
The length of f is about 4.3 inches.