SOLUTION: A point Y is 400m north-west of X. A tree is north-east of Y and on a bearing 015° from X. Find the distance of the tree from a) X b) Y

Algebra ->  Test -> SOLUTION: A point Y is 400m north-west of X. A tree is north-east of Y and on a bearing 015° from X. Find the distance of the tree from a) X b) Y      Log On


   



Question 1205425: A point Y is 400m north-west of X. A tree is north-east of Y and on a bearing 015° from X. Find the distance of the tree from
a) X
b) Y

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A point Y is 400m north-west of X. A tree is north-east of Y and on a bearing 015° from X. Find the distance of the tree from
a) X
b) Y
---------------
Call the tree point T.
Assuming by NW you mean a bearing of 315 degs:
-----
Angle Y = 90 degs
Angle X = 60 degs
Angle T = 30 degs
================
Use the Sine Law:
400/sin(30) = XT//sin(60)
800 = XT/sin(60) = XT*2/sqrt(3) = 800/sqrt(3) = ~461.88 meters
===========================
------------
XT = sqrt(XY^2 + YT^2) = ~ 516.4 meters
////////////////////////////////////////////////////////
Working with bearings (compass headings) can be confusing.
To change to angles wrt the x-axis, subtract from 450.
eg, 450 -315 --> 135 degs wrt the x-axis
450 - 15 ---> 435, so subtract 360 --> 75
450 - 135 = 315.
315 - 360 = -45