A helicopter on a joy flight over Kakadu National Park
travels due east for 125 km, then on a bearing of 215
for 137 km before returning to its starting point. Find the
total length of the journey, correct to the nearest kilometre.

The interior angle at the first turning point in the triangular flight path has measure 270° -215° = 55°. The law of cosines can be used to find the length of the final leg:

c² = a² +b² -2ab·cos(C)

c = √(125² +137² -2·125·137·cos(55°)) ≈ √14749.01 ≈ 121.4

The total length of the journey is then ...

round trip = 125 +137 +121.4 = 383.4 . . . km

___

In the attachment, the number at the bottom is the sum of the lengths of the two adjacent sides. The total length is then 125 +258.4 = 383.4 km.

A helicopter on a joy flight over Kakadu National Park travels due east for 125 km, then on a bearing of 215 for 137 km before returning to its starting point. Find the total length of the journey, correct to the nearest kilometre.

Respuesta :

Otras preguntas

A helicopter on a joy flight over Kakadu National Park
travels due east for 125 km, then on a bearing of 215
for 137 km before returning to its starting point. Find the
total length of the journey, correct to the nearest kilometre.