CPM Homework Help : CC3MN Problem 9-15

Eric set up this ratio for two similar triangles:

$\frac { x } { 12 } = \frac { 5 } { 9 }$

He solved the problem and found $x ≈ 6.67$ . What was his mistake?

Hint:

Examine the ratios Eric created. Did he set up his ratios correctly?

2 triangles in same orientation labeled as follows: Larger, left side, 9, & bottom side, x, Smaller, left side, 5, & bottom side, 12.