论文部分内容阅读
三角形的外角与其不相邻的内角有如下的关系:不等量关系:三角形的外角大于任何一个与之不相邻的内角。下面就举例说明这个定理不等量关系在解题中的具体应用。一、直接应用定理例1如图1所示,∠1、∠2、∠3的大小顺序正确的是()。A.∠1>∠2>∠3B.∠1<∠2<∠3C.∠1>∠3>∠2D.∠2<∠1<∠3解析:仔细观察图形,知道∠3是△EDC的一个外角,∠2是
The external angle of a triangle and its non-adjacent internal angle have the following relationship: Unequal relationship: The external angle of a triangle is greater than any internal angle that is not adjacent to it. The following example illustrates the specific application of the theorem inequality relations in the problem solving. First, the direct application of the Theorem Example 1 shown in Figure 1, ∠ 1, ∠ 2, ∠ 3 is the correct order of size (). A. ∠1> ∠2> ∠3B. ∠1<∠2<∠3C.∠1> ∠3> ∠2D. ∠2<∠1<∠3 Analysis: Observe the pattern carefully and know that ∠3 is △EDC. An outside corner, ∠2 is