Answer:
The length of segment DC is 33 unit.
Explanation:
As given
The length of segment BC is 23 units.
As given in the figure .
AB = 2x + 7
AB = BC
2x + 7 = 23
2x = 23 - 7
2x = 16

x = 8
In the Δ ABD and ΔCBD
(1) AB = BC
(As given in the figure.)
(2) ∠DBA = ∠DBC = 90°
(3) BD = BD
(Common side of both the triangle.)
Thus by using SAS congurence property .
Δ ABD ≅ ΔCBD
Thus
AD = DC
(Corresponding sides of the congurent triangle.)
Thus
AD = 4x + 1
Put x = 8
AD = 4 × 8 + 1
= 32 + 1
= 33 unit
Thus AD = DC = 13 unit
Therefore the length of segment DC is 33 unit.