3) Whenever you have in a triangle 2 known sides and the angle comprise between those side, then you apply the law of cosine to calculate the 3rd side:
BC² = AB² + AC² - 2AB.BC.cos(25.6)
BC² = 306² + 275² - 2(306).(275).cos(25.6)
BC² = 93,636 + 75,625 - 168,300.(0.901833), note that cos(25.6) = 0.901...]
BC² = 17,482.6 and BC = √17,482.6 → BC = 132.22 m or 132 (rounded)
Number 6 and 9 follow the same methodology.
Hope it helped you
