Answer:
B: 50 feet
Explanation:
Let A represents the location of the swing, B represents the location of bench and C represents the position of slide,
According to the question,
AB = 100 ft,
BC = 80 ft,
m∠ABC = 30°,
By the cosine law,
![AC^2=AB^2+BC^2-2* AB* BC* cos 30^(\circ)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/l0dk4ldnbqthjx7smzjgkmnoujd7bc6f5o.png)
![=100^2+80^2-2* 100* 80* (√(3))/(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/dg1vm0nikcaiajhzyfz85ywldmjds894f2.png)
![=10000+6400-8000√(3)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ys0tjuoda4ogf1qfp9eaupb67jpy6ootot.png)
![=2543.59353945](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4nt6tkv79lv7vbjl4tlziwdg0011jkjo54.png)
![\implies AC=50.434051388\approx 50](https://img.qammunity.org/2019/formulas/mathematics/middle-school/vvcrjxaj84mcxdxqemyvefa0v6meib8odc.png)
Hence, the approximately distance between the swing and the slide is 50 ft.
Option 'B' is correct.