A:Can you tell me how many kinds of triangles can be divided according to their angles?

A:你能告訴我三角形按角的大小可以分成哪幾類嗎?

B:Obtuse triangles，acute triangles and right triangles.

B:鈍角三角形、銳角三角形和直角三角形。

A:Yes. Angles that are less than 90° are called acute angles.  Angles that are more than 90° and less than 180° are called obtuse angles.

A:是的。比90°小的角是銳角。比90°大而比180°小的角是鈍角。

B:A right triangle contains a 90° angle indicated by a small square.

B:直角三角形含有一個直角，用一個小正方形表示。

A:How many kinds of triangles can be divided according to their sides?

A:三角形按邊的長短可以分成哪幾類?

B:Scalene  triangles，isosceles  triangles  and equilateral triangles.

B:不等邊三角形、等腰三角形和等邊三角形。

A:An isosceles triangle has two sides the same length. Its two base angles are equal.。

A:等腰三角形有兩條邊長度相等，它的兩個底角相等。

B:An equilateral triangle has all its sides equal. The interior angles of an equilateral triangle are all 60°.

B:一個等邊三角形所有的邊都相等。等邊三角形的內(nèi)角都是60°.去看看：少兒英語表演節(jié)目