Question

This needs a little working out. Just part A to simplify to find 21.

Answer 1

see explanation

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 =
`(13)/(10)` = 1.3