The naming convention in a congruence statement is very specific.
m∠ S=48^(∘) Explanation: See solution.
Practice makes perfect
The naming convention in a congruence statement is very specific. Corresponding vertices have to be presented in the same order. If we examine our congruence statement, we see that ∠ S corresponds to ∠ Y.
△ QR S ≅ △ XZ Y
In the diagram, ∠ S has been paired with ∠ Z which is incorrect! To find m∠ Y, we have to subtract the know angles in △ XZY from 180^(∘).
m∠ Y + 90^(∘) +42^(∘) = 180^(∘) ⇔ m∠ Y =48^(∘)
Now we can rewrite the given statement.
&∠ S≅ ∠ Y
&m∠ S = m∠ Y
&m∠ S = 48^(∘)
