Given: In Δ XYZ, XY ≅ XZ, m∠ Y = (2x + 7)° and m∠ Z = 45°

In Δ XYZ,

XY ≅ XZ

⇒ ∠ Y ≅ ∠ Z (Angles opposite to congruent sides of a

triangle are also congruent)

⇒ m∠ Y ≅ m∠ Z

⇒ (2x + 7)° = 45°

2x + 7 = 45

⇒ 2x = 45 – 7 (Transposing 7 to RHS)

2x = 38

⇒ x = (Transposing 2 to RHS)

x = 19

∴ The value of x is 19°.