Answer:
10x + 8 = 21
x = 1.3
Step-by-step explanation:
a)
In pentagon ABCDE,
AB = DE = 2x + 3 and BC = CD = x + 1
Perimeter of pentagon ABCDE = 21
4x + 2(2x + 3) + 2(x + 1) = 21
4x + 4x + 6 + 2x + 2 = 21
[tex] \purple {\boxed {\bold{10x + 8 = 21}}} [/tex]
b)
10x = 21 - 8
10x = 13
[tex]x = \frac{13}{10} \\ x = 1.3 \: cm [/tex]
