Question

Find the measure of angle D. Round to the nearest tenth.

Answer 1

You use the cosines for sss. Because you are trying to find angle D start with (next post)

Answer 2

https://www.mathsisfun.com/algebra/trig-solving-sss-triangles.html
Here is a link to help you through the rest so you can study and better understand for future problems.

Answer 3

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Answer 4

cos D = (f2 + e2 − d2) / 2fe

Now you just fill in the blanks and it will be solved.

Answer 5

You can even solve each step on here and I will let you know if you're right