OG详解-OG9 数学2 Q57

Choice C is correct. It’s given that triangle XYZ is similar to triangle RST, such that X, Y, and Z correspond to R, S, and T, respectively. Since corresponding angles of similar triangles are congruent, it follows that the measure of ∠Z is congruent to the measure of ∠T. It’s given that the measure of ∠Z is 20。Therefore, the measure of ∠T is 20。
Choice A is incorrect and may result from a conceptual error. Choice B is incorrect. This is half the measure of ∠Z. Choice D is incorrect. This is twice the measure of ∠Z.