Part A
For the triangle
A=(B*h)/2 A=24
B=3*h
A=(3*h)*h/2 =(3*h^2)/2=243*h^2=48 h^2=16 h=4 B=3*4 B=12
the height and base of the poster are h=4 and B=12 respectively
Part B
For the rectangle
Area A=L*W
L=5+W A=L*W=24 A=L*W=(5+W)*W = 5*W+W^2 5*W+W^2=24 W^2+5*W-24=0 (W-3)*(W+8) =0Only positive W values make sense here
(W-3)=0 W=3 L=5+W L=5+3 L=8