Answer
$x=12$ units
Work Step by Step
Step 1: Since the triangles are similar, their corresponding sides are in
proportion.
Step 2: This means that $\frac{6}{18}=\frac{4}{x}$.
Step 3: Solving through cross multiplication, $6x=18\times4$.
Step 4: $6x=72$.
Step 5: $x=12$ units.
Check:
Step 1: Equating the two proportions to see if they reduce to the same fraction, $\frac{6}{18}=\frac{4}{12}$.
Step 2: Simplifying both sides, $\frac{1}{3}=\frac{1}{3}$.
Step 3: Therefore, the answer is accurate.