Question

WILL GIVE BRAINLIEST

Answer 1

Answer:

3

Step-by-step explanation:

These are similar triangle

We can use ratios to solve

12         12+4

------ = ----------

9         9+DC

Using cross products

12( 9+DC) = 9*(12+4)

12 (9+DC) = 9*16

Divide each side by 12

12/12 (9+DC) = 9*16/12

9+DC = 12

Subtract 9 from each side

9+DC-9 =12-9

DC =3

Answer 2

Answer:

3 units

Step-by-step explanation:

We can see that triangle ADE is similar to triangle ACB.

Therefore the ratios of the lengths of their sides must be equal.

We can write AD/AC = AE/AB

we are given AD = 9, AE = 12 and AB = 12 + 4 = 16

Substituting the above values into the equation:

AD/AC = AE/AB

9 / AC = 12/16  (rearranging)

(AC)(12) = (9)(16)

AC = (9)(16)/12

AC = 12

We can also see that

DC = AC - AD

DC = 12 - 9

DC = 3 units