# Supplemenary angles 2x+8 and x-24 add up to 179.99 degrees but they must add up to 180 degrees. What do I do?

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### 3 Answers

Since the angles are supplementary, they must add up to 180 degrees.

2x + 8 + x - 24 = 180

3x - 16 = 180

3x = 196

x = 65.33

Now, I assume you checked your answer using 65.33 as your value for x.

2(65.33) + 8 + 65.33 - 24 = 179.99

You got 179.99 because of rounding. The variable x does not actually equal 65.33 because the 3 is a repeating decimal. Instead of rounding, use the fraction 196/3. This is equal to 65.333333333333.... etc... Now try checking.

2(196/3) + 8 + 196/3 - 24 = 180

Without rounding, you get the required answer of 180 degrees.

I hope this helped! :)

Numerically speaking, 179.99 can be rounded off to 180. In this case, you can add up (2x+8) + (x-24)= 179.99

so, you can have 3x-16=179.99

this will give **65.33 as the value of x**

On the other hand, if you use (2x+8) + (x-24) = 180, you will get **65.3333333333 as the value of x**.

Following the rules in rounding off, this value will be **65.33, the same answer for 179.99**

In addition, if you will follow the rules in significant figures, in either value (179.99 or 180), you will simply **get 65**

Thank you. :) I knew that the variable x wasn't exactly 65.33 because it is a repeating decimal but I still don't see how it can be 180. I don't mean to seem obtuse but to me to get 180 degrees you have to round 179.99 up to 180.