Question

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

Answer 1

Distance between Amanda and Angela (c) = 4.30 km (Approx)

Explanation:

Given:

Amanda rides (a) = 10 km

Angela rides (b) = 12 km

Angel between them = 20°

Find:

Distance between Amanda and Angela (c)

Computation:

Using law of cosines:

c² = a² + b² - 2abCosФ

c² = 10² + 12² - 2(10)(12)Cos20°

c² = 100 + 144 - 2(10)(12)(0.9397)

c² = 244 - 225.528

c² = 18.472

c = 4.2979

Distance between Amanda and Angela (c) = 4.30 km (Approx)