Q8 of 12 Page 203

Two trees A and B are on the same side of a river. From a point C in the river, the distance of the trees A and B is 250 m and 300 m respectively. If the angle C is 45o find the distance b/w the trees (use root 2 = 1.44).

The figure is given below:



In ΔABC


∠C = 45


AC = 250 m


BC = 300m


Using cosine rule


a2 = b2 + c2 – 2bc cos A


so, AB2 = AC2 + BC2 – 2 AC x BC cos C


= 2502 + 3002 – 2 x 250 x 300 x cos 45


AB2 = 46433.98


AB = 215.5 m


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