Identify the correct explanation and the similarity statement for the similar triangles. A: By the Isosc. Δ Thm., ∠B ≅ ∠C, so by the Def. of ≅, m∠B = m∠A.
This gives m∠A = 75° by Substitution.
Then, by the Δ Subt. Thm., m∠C = 30°.
Now apply the Isosc. Δ Thm. and the Δ Subt. Thm. to ΔPQR to find that m∠P = m∠Q = 75°.
Therefore ΔABC ~ ΔPQR by SSS ~.

B: By the Isosc. Δ Thm., ∠B ≅ ∠C, so by the Def. of ≅ , m∠B = m∠C.
This gives m∠C = 75° by substitution.
Then, by the Δ Sum Thm., m∠A = 30°.
Now apply the Isosc. Δ Thm. and the Δ Sum Thm. to ΔPQR to find that m∠P = m∠Q = 75°.
Therefore ΔABC ~ ΔPQR by AA ~.

C: By the Isosc. Δ Thm., ∠B ≅ ∠C, so by the Def. of ≅, m∠B = m∠C.
This gives m∠C = 30° by Substitution.
Then, by the Δ Subt. Thm., m∠A = 75°.
Now apply the Isosc. Δ Thm. and the Δ Subt. Thm. to ΔPQR to find that m∠P = m∠Q = 75°.
Therefore ΔABC ~ ΔPQR by SSS ~.

D: By the Isosc. Δ Thm., ∠B ≅ ∠C, so by the Def. of ≅, m∠B = m∠A.
This gives m∠A = 75° by Substitution.
Then, by the Δ Sum Thm., m∠C = 30°. Now apply the Isosc. Δ Thm. and the Δ Sum Thm. to ΔPQR to find that m∠P = m∠Q = 75°.
Therefore ΔABC ~ ΔPQR by AA ~.