Question

Amanda rides her bike east for 10 km. Angela rides her bike 20 degrees south of east 12 km. How far apart are they? Round to the nearest tenth

Answer 1

`4.3\ km`

Explanation:

we know that

Applying the law of cosines

`c^(2)=a^(2)+b^(2)-2(a)(b)cos(C)`

we have

c-----> is the distance between Amanda and Angela

`a=10\ km`

`b=12\ km`

`C=20\°`

substitute the values

`c^(2)=10^(2)+12^(2)-2(10)(12)cos(20\°)`

`c^(2)=18.4738`

`c=4.3\ km`