直角三角形

Prepare a piece of paper, and fold it right-angled the triangle.

准备一张纸，把它折成一个直角三角形。

Expressed as a ratio of the sides of right-angled triangle containing the ''.

直角三角形各角的函数是用各边的比来表示的。

Square on longest side of a right-angled triangle equals stun of the square s on other two sides.

直角三角形最长边的平方等于另两边的平方的和。

Square on longest side of a right-angled triangle equals stun of the squares on other two side s.

直角三角形最长边的平方等于另两边的平方的和。

Given the lengths of the two sides of a right-angled triangle, we can find out the length of a third side.

要是知道直角三角形两个边的长度，我们就能求出第三边的长度。

Square on longest side of a right-angled triangle equals stun of the squares on other two sides.

直角三角形最长边的平方等于另两边的平方的和。

Fold but do not fold into a right-angled triangle the intermediate is not it?

不用对折而是把中间折叠成直角三角形是么？

Given the lengths of the two sides of a right-angled triangle, wecan find out the length of a third side.

要是知道直角三角形两个边的长度，我们就能求出第三边的长度。

Look at Picture 3.4—2. Compare the area of Square ABCD with the sum of the areas of four same right-angled triangles , and what inequality can you have?

阅读课本 P110，比较图3.4－2中正方形 ABCD 的面积与4个全等的直角三角形的面积之和的大小，你能得到怎样的不等式？

Note that this ratio does not depend on the particular right triangle chosen, as long as it contains the angle A , since all those triangles are similar.

把直角三角形的弦放在直径上，股就是长的弦，即正弦，勾就是短的弦，即余下的弦——余弦。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。