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# a plane flies on a bearing of 065 for 200km how far east has it gone

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a plane flies on a bearing of 065 for 200km how far east has it gone

Guest Jan 18, 2015

#1
+17746
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Bearing is measured clockwise from north.

However, trig is measured counterclockwise from east.

So a bearing of 65° translates to a trig angle of 25°.     (90° - 65° = 25°)      (Everything is in Quadrant I.)

Picture a right triangle that has an endpoint at the origin, a 25° angle going to the upper right, a hypotenuse of 200, and a base along the x-axis. You want to find the length along the x-axis.

East is along the x-axis, so use cos:  cos(25°)  =  x/200   --->   x  =  200cos(25°)   --->   x  =  181 km

geno3141  Jan 18, 2015
#1
+17746
+5

Bearing is measured clockwise from north.

However, trig is measured counterclockwise from east.

So a bearing of 65° translates to a trig angle of 25°.     (90° - 65° = 25°)      (Everything is in Quadrant I.)

Picture a right triangle that has an endpoint at the origin, a 25° angle going to the upper right, a hypotenuse of 200, and a base along the x-axis. You want to find the length along the x-axis.

East is along the x-axis, so use cos:  cos(25°)  =  x/200   --->   x  =  200cos(25°)   --->   x  =  181 km

geno3141  Jan 18, 2015