If m∠A = m∠B and m∠A + m∠C = ∠D, then m∠B + m∠C = ∠D Which property is shown?

Substitution Property

Step-by-step explanation:

So we know that:

And we also know that:

And by using a specific property, we get that:

Essentially, we substituted B for A.

So, this is an example of the substitution property, where if two sides/angles are congruent, we can substitute them for each other.

dc=6 square root of 3 and ac is 12 square root 3

c and d

step-by-step explanation:

square root of 3/2 = 18/c

cross multiply to get 18*2=√3*c

36/√3 * √3/√3 = c

c= 36*√3/3

c=12√3