数学题：一个三角形被一个长方形挡住了，如图。它是（　）

A.直角三角形

B.锐角三角形

C.钝角三角形

D.三种三角形都有可能

数学题解答：答案为D。三种三角形都有可能。因为已经露出了一个锐角，但是不管是直角三角形、锐角三角形、钝角三角形都至少有两个锐角，所以无法判断它是哪种三角形。

推荐阅读：
The Image Flood Fill Algorithm (C++)　 How to Clone a Graph in C++/Java using Depth First Search Algori　 The Unique Morse Code Words Algorithm　 The Algorithm to Find Anagram Mappings between Two Arrays　 How to Write More Readable Blog Posts　 Due.com Review: It Really Is An Easy Way to Keep Track of Your I　 Twitter Mishaps: The Infamous, The Insensitive, and the Unfunny　 Standing Out from the Crowd: How to Get Your Content Noticed in 　 How to Leverage Social Media for Events to Achieve Your Goals　 Grammar-Geeking Tools for Clearer Blog Content