Please help me!
Look at this diagram.

Step-by-step explanation:

First, notice that ∠BCD and ∠DCE form a linear pair. Linear pairs sum to 180°. Therefore:

And since we know that ∠BCD measures 130°:

And since ∠DCE and ∠BCA are vertical angles:

Therefore, by definition:

Looking at the left triangle, we can see that BC and AC both have one tick mark. This means that they are congruent. Therefore, ΔABC is an isosceles triangle. The two base angles of an isosceles triangle are congruent. Hence:

The interior angles of a triangle must total 180°. So:

Substitute in known values:

Simplify:

Divide both sides by two:

Substitute:

Therefore:

Similarly, for the triangle on the right, we can write that:

Substitute:

Combine like terms:

Since we determined that x = 13:

Simplify:

Therefore:

And by dividing both sides by 10:

d

step-by-step explanation:

12cm

the answer is d