Multiple choice

Triangle ABC is such that AB=9 cm, BC=6 cm,AC=7.5 cm. Triangle DEF is similar to $\Delta ABC$. If EF=12 cm then DE is :

  1. 6 cm

  2. 16 cm

  3. 18 cm

  4. 15 cm
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Triangles are similar, so AB/DE = BC/EF = AC/DF. 9/DE = 6/12. 9/DE = 1/2. DE = 18.

AI explanation

Because triangle DEF is similar to triangle ABC, their corresponding sides are proportional, which gives the ratio DE/AB = EF/BC. Substituting the given values yields DE/9 = 12/6. Solving this equation gives DE = 18 cm.

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