For which value of x is each figure a kite?

SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Desrcibe the property of a kite
Kite has 2 diagonals that intersect each other at right angles (90 degrees)
STEP 2: Translate the property in Step 1
[tex]\begin{gathered} \text{From the theorem above, } \\ (6x+6)^{\circ}=90^{\circ} \end{gathered}[/tex]STEP 3: Solve for x
[tex]\begin{gathered} (6x+6)^{\circ}=90^{\circ} \\ 6x+6=90 \\ \text{Subtract 6 from both sides} \\ 6x+6-6=90-6 \\ 6x=84 \\ \text{Divide both sides by 6} \\ \frac{6x}{6}=\frac{84}{6} \\ x=14 \end{gathered}[/tex]Hence, the value of x is 14