On monday, amie rides her bike from home to school. after school, she bikes to work. after work, she bikes home. based on the information in the diagram below, about how many miles does amie bike on monday? 10.9 mi. 11.3 mi. 12.7 mi. 13.1 mi.

Let the distance between the school and work = d //
Using the cosine law to find d //

d² = 4.5² + 2.5² - 2 *2.5 *4.5 cos 120 = 37.75 // ∴ d = √37.75 = 6.14
∴ Total distance = 6.14 + 2.5 + 4.5 = 13.14
The correct choice is the fourth option ⇒⇒⇒⇒ 13.1 mi