Question

topic: triangles
a flashlight is projecting a triangle onto a wall, as shown below.
the original triangle and its projection are similar. what is the missing length n on the projection?
26
30
13\frac{1}{3}
10\frac{4}{5}

Explanation:

Step1: Set up proportion

Since the two triangles are similar, the ratios of corresponding sides are equal. We have the proportion $\frac{12}{20}=\frac{18}{n}$.

Step2: Cross - multiply

Cross - multiplying gives us $12n = 20\times18$.

Step3: Calculate the right - hand side

$20\times18=360$, so $12n = 360$.

Step4: Solve for n

Dividing both sides by 12, $n=\frac{360}{12}=30$.

Answer:

30