<u>Answer:</u>
a = 8.1
<u>Step-by-step explanation:</u>
Use the cosine rule:
Substituting the values:
⇒
⇒
The least number should always start off with negatives if there are any. In this case there is so we can start with -2 as our least amount. Next are the small fractions. If you're allowed a calculator, I would use that to find what the decimals will look like for each fraction:
After -2 the next least number is 0 and the next one is the fraction or decimal closest to the number 0 which is 0.4
The next number would be from the fractions we solved earlier. 0.5 and 0.625 would follow 0.4 and then 1.1 and 1.6667(solved for from fraction).
Here is the list:
Hope this helps!
I think the correct answer from the choices listed above is option B. Quadrilateral ABCD must be a rectangle because it is characterized by having <span>opposite sides that are parallel and side AB congruent to side DC which are characteristics of a rectangle.</span>