Trigonometry help

Question

dave is standing across the street from a building. If he is 10 m and 30 degrees from one corner of the building,  and 24 m and 10 degrees from the other corner of the building, what  is the length,l, to the nearest tenth of a metre

Answer 1

Without a picture, there is an ambiguity in the question, so I’ll supply two possible solutions, both of which use the cosine rule.

l²=10²+24²-2×10×24cosA, where A is 30-10=20º or 30+10=40º.

l=15.0m or 17.6m.