Please help!! Cause I’m not smart

In the proof of the triangle angle sum theorem, you must draw an auxiliary line. which construction must you use to draw this line?

What is the standard form of -5x^2+2x^4-11+x^3+3x

The spring the owner of a sporting good store decreases the price of winter gloves from $10 to $8 each increases the price of swimming goggles from $8 to $10 without doing the math you think the percent decrease in the price of the gloves the same as the percent increase of the goggles explain why or why not