SAT官方每日一题 2017年7月6日.

SAT试题类型 Writing > Identifying Sentence Errors Mathematics > Standard Multiple Choice Read the following SAT test question and then click on a button to select your answer. In the figure above, O is the center of the circle and triangle A B O is equilateral. If the sides of triangle A B O are of length 6, what is the length of line B C? (A) 3 times square root 3 (B) 4 times square root 3 (C) 6 times square root 3 (D) 9 (E) 12 答案:C Explanation Choice (C) is correct. Since triangle A B O is equilateral, each of its angles has measure 60 degrees. It follows that angle B O C has measure 120 degrees. Since line O B and line O C are radii of the same circle, they are of equal length, and so delta O C B is isosceles. Hence angle O B C and angle O C B each have measure 30 degrees. Thus angle A B C has measure 60 degrees + 30 degrees = 90 degrees, and so triangle A B C is a 30 degrees minus 60 degrees minus 90 degrees right triangle. Since line A B, the side opposite the 30 degrees angle in triangle A B C, is of length 6, it follows that line B C, the side opposite the 60 degrees angle, is of length 6 times square root 3 相关阅读 SAT官方每日一题 2011年7月6日 SAT官方每日一题 2011年7月5日 SAT官方每日一题 2011年7月4日 SAT官方每日一题 2011年7月3日 SAT官方每日一题 2011年7月2日 SAT官方每日一题 2011年7月1日