Respuesta :

Answer:

y ≈ 5.2

Step-by-step explanation:

∠ F = 180° - (42 + 48)° ← sum of angles in a triangle

∠ F = 180° - 90° = 90°

Thus Δ DEF is right at F

Using the sine ratio in the right triangle

sin48° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{DF}{DE}[/tex] = [tex]\frac{y}{7}[/tex] ( multiply both sides by 7 )

7 × sin48° = y , then

y ≈ 5.2 ( to the nearest tenth )