I forgot how to do this can someone tell me how I do this again? Please Lol

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.

The equation of a parabola is given. y=18x2+4x+20 what are the coordinates of the focus of the parabola?

The mass of a marine organism, in pounds, p years after it is born is given by the polynomial function r(p) = -4p2 + 300p. find the mass when p = 20 years.