ASAP PLEASE HELP!! SCALE FACTOR! EASY!!

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

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.