Respuesta :

The answer is 7 apex

Answer-

The length of PR is 7 units.

Solution-

Given,

in the ΔDEF,

m∠D = 25°, m∠E = 114°, DF = 21, DE = 15

in the ΔPQR,

m∠P = 25°, m∠Q = 114°, PR = x, PQ = 5

So, ΔDEF ~ ΔPQR by AA (Angle-Angle) similarity, as

  1. m∠D = m∠P = 25°
  2. m∠E =m∠Q = 114°

So, according to similarity

[tex]\Rightarrow \dfrac{DF}{PR}=\dfrac{DE}{PQ}=\dfrac{EF}{QR}[/tex]

Putting the values,

[tex]\Rightarrow \dfrac{21}{x}=\dfrac{15}{5}[/tex]

[tex]\Rightarrow x=\dfrac{21\times 5}{15}[/tex]

[tex]\Rightarrow x=7[/tex]