Answer:
DE = 20units
Step-by-step explanation:
In Δ ABC,
angle A is congruent to angle B.... (given)
therefore, ΔABC is an isoceles triangle.
therefore, CA = CB..... (side opposite to congruent angles are congruent in an isoceles triangle)
therefore, CB = 4 units
In ΔCDE,
angle D is congruent to angle E.... (given)
therefore, ΔCDE is an isoceles triangle.
therefore, CD = CE
therefore, CD = 8 units
ΔCDE ~ ΔCBA
therefore,
[tex] \frac{cd}{cb} = \frac{ce}{ca} = \frac{de}{ab} \\ therefore \: \frac{8}{4} = \frac{8}{4} = \frac{de}{10 } \\ therefore \\ \frac{2}{1 } = \frac{de}{10 } \\ de \: = 2 \times 10 = 20units[/tex]