Answer:
see explanation
Step-by-step explanation:
Since the pentagon has one line of symmetry. This will be a vertical line through C, thus
CD = BC = x + 1 and ED = AB = 2x + 3
Perimeter = AE + ED + DC + CB + BA
= 4x + 2x + 3 + x + 1 + x + 1 + 2x + 3 = 10x + 8
Perimeter is given as 21, thus
(b)
10x + 8 = 21 (subtract 8 from both sides )
10x = 13 ( divide both sides by 10 )
x = [tex]\frac{13}{10}[/tex] = 1.3