Question

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Answer 1

Answer:

20.7 correct rounding for odyssey

Step-by-step explanation:

Answer 2

$\bf \textit{Law of Cosines}\\ \quad \\ c^2 = {{ a}}^2+{{ b}}^2-(2{{ a}}{{ b}})cos(C)\implies c = \sqrt{{{ a}}^2+{{ b}}^2-(2{{ a}}{{ b}})cos(C)}\\\\ -----------------------------\\\\ \begin{cases} a=12\\ b=10\\ D=90+50 \end{cases}\implies d = \sqrt{{{ 12}}^2+{{ 10}}^2-2(12)(10)cos(140^o)} \\\\\\ d\approx \sqrt{427.851}\implies d\approx 20.684551$