If humans started burning half as many fossil fuels as we did in 2004, what might the graph look like?

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

Abcd is a square. what is the measure of angle bac

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.