Respuesta :

Answer:

8.6

Step-by-step explanation:

Use the law of cosines

[tex]d^{2} = e^{2} + f^{2} -2ef cos D[/tex]

[tex]d^{2} = 9^{2} + 13^{2} - 2(9)(13) cos 41\\ = 81 + 169 - 176.602\\ = 73.3979\\d = \sqrt{73.3979} = 8.6[/tex]