I made a side view diagram, with A and B the points on the lake, obviously A farther away from the tower. I labeled my tower DC , C as the base of the tower.
In Triangle ABD, angle A = 7°, angle ABD = 167° , angle ADB = 6° , and AB = 1 km
by the sine law:
BD/sin7 = 1/sin6
BD = sin7/sin6 = 1.16589... (keep number in calculator's memory)
Now in the right-angled triangle, BCD
DC/BD = sin13
DC = 1.16589..(sin13) = .26226 km
or appr 226 m
From an observation tower that overlooks a small lake, the angles of depression of point A, on one side of the lake, and point B, on the opposite side of the lake are, 7degrees and 13degrees, respectively. The points and the tower are in the same vertical plane and the distance from A to B is 1km. Determine the height of the tower.
3 answers
A children's play area is triangular the sides of the play area measure 100m 250m and 275 respectively. Calculate the area of the play area
Triangle is A-B 275m, B-C 250m, A-C 100m
First use a^2-b^2-c^2/-2bc=CosA
Then this to calculate area A=(1/2) bc SinA
Answer should be A=12,479m^2
Good Luck
First use a^2-b^2-c^2/-2bc=CosA
Then this to calculate area A=(1/2) bc SinA
Answer should be A=12,479m^2
Good Luck
6 answers