sketch a right-angled triangle.
On the horizontal base mark W for Wes.
let the fireworks be at P and let Q be the point below P, so that angle Q = 90°
let the angle at W be 28°
let A for Abby be a point between W and Q so that angle PAQ = 40° , and AW = 20
Look at triangle PWA , angle WAP = 180-40 = 140°
,
which makes angle WPA = 12°
By the Sine Law, we can find AP
AP/sin28 = 20/sin12
AP = 20sin28/sin12 = ....
Now in the right-angled triangle AQP
cos 43 = AQ/AP
where AQ is the distance that Abby is from the base of the fireworks.
Word problem: Wes saw fireworks at 28 degrees; Abby (who was standing 20 m away from him) saw the same fireworks at a 40 degree angle. Where was Abby standing? (The answer is 61.8m, but I don't know how to figure it out or sketch the triangle).
1 answer