Q20:

y°

x°

z°

图贴不上来，x°，y°，z°分别是一个三角形的三个外角。

In the figure shown, what is the value of x?

(1) y = x

(2) z = x

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer: Thanks!

C.

条件1可以知道三角形是等腰.但是不知道底角和顶角关系,不充分

条件2同1.不充分

条件1.2联合知道三角形是等边.X=120.