Respuesta :

Answer:

  • 3 m

Step-by-step explanation:

The formed triangles are similar and the ratio of corresponding sides is equal:

  • x/4 = 9/12
  • x/4 = 3/4
  • x = 3 m

The light source should be at 3 m height

Both triangles are congruent so

[tex]\\ \bull\sf\longmapsto \dfrac{x}{4}=\dfrac{9}{12}[/tex]

[tex]\\ \bull\sf\longmapsto 12x=36[/tex]

[tex]\\ \bull\sf\longmapsto x=3[/tex]

Light source should be at 3m