Question

a boat leaves port and sails due west for 10km
it then sails 6km south-west before returning directly to port
use the cosine rule to find how far the return journey is

white rose maths

Answer 1

Answer:

14.86 km to the nearest hundredth.

Step-by-step explanation:

The angle between the 2 directions is 90 + 45 = 135 degrees,

so if the required distance is x, we have using the Cosine Rule:

x^2 = 10^2 + 6^2 - 2*6*10cos135

= 220.853

x = 14.86 km.