HELP ME I NEED HELP I DO NOT UNDERSTAND THIS :')

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