SAT推理測(cè)驗(yàn)（SAT Reasoning Test）是美國(guó)大學(xué)錄取中的一個(gè)標(biāo)準(zhǔn)化測(cè)試�？疾鞂W(xué)生的能力是否足夠適應(yīng)大學(xué)教育。

   Read the following SAT test question and then click on a button to select your answer.

   In zhe figure above, the circle with center A and the circle with center C are tangent at point D. If the circles each have radius 10, and if line l is tangent to the circle with center A at point B, what is the value of x？

　　(A) 50

　　(B) 60

　　(C) 63

　　(D) 65

解析Explanation：

   The circles each have radius 10, so A B = A D = D C = 10. Since the circles are tangent at point D, segment Line AC contains D and A C = 20. Also, line A B and l are perpendicular because a line tangent to a circle forms a right angle with the radius at the point of tangency. Therefore, triangle A B C is a right triangle with hypotenuse 20 and side line A B of length 10. A right triangle with one side of length one-half that of its hypotenuse is a 30 degree - 60 degree - 90 degree triangle. The 30 degree angle is opposite side line A B, so x = 90 minus 30 = 60.

   SAT會(huì)測(cè)驗(yàn)學(xué)生們將在學(xué)校學(xué)到的知識(shí)付諸實(shí)踐運(yùn)用分析、解決問(wèn)題的能力。關(guān)注更多內(nèi)容進(jìn)入SAT培訓(xùn)網(wǎng)！

聲明：我方為第三方信息服務(wù)平臺(tái)提供者，本文來(lái)自于網(wǎng)絡(luò)，登載出于傳遞更多信息之目的，并不意味著贊同其觀點(diǎn)或證實(shí)其描述，文章內(nèi)容僅供參考。如若我方內(nèi)容涉嫌侵犯其合法權(quán)益，應(yīng)該及時(shí)反饋，我方將會(huì)盡快移除被控侵權(quán)內(nèi)容。