The two distinct parabolas y=x²+ax+b and y=x²+bx+a intersect the axes at A,B,C,D,E as shown and meet at B on the horizontal axis. A=(−8,0). Find the area of quadrilateral ADCE.
A regular polygon is divided into 18 congruent pentagons as shown; all sides of each pentagon are equal. If k,ℓ are the two largest angles of one pentagon, find k+ℓ in degrees.