about maths....

(1) 等腰三角形底角相等in english係咩?
Ans:
如果你想答題時引用原因，可以用呢個：
base ∠s, isos. △

英文全寫就係：
The base angles of an isosceles triangle are equal


(2) 等邊三角形三隻角相等in english?
如果你想答題時引用原因，可以用呢個：
prop. of equi. △

英文全寫就係：
The angles of an equilateral triangle are all equal.


(3) 三角形外角和in english?
如果你想答題時引用原因，可以用呢個：
ext. ∠ of polygon
（其實所有多邊形的外角和都是360度，所以原因中亦只需用polygon）

英文全寫就係：
The sum of exterior angles of a triangle is 360 degrees.


(4)三角形內角和in englsih?
如果你想答題時引用原因，可以用呢個：
∠ sum of △

英文全寫就係：
The sum of interior angles of a triangle is 180 degrees.


希望以上可以幫倒你！^^

1)The base angles of an isosceles triangle are equal
2)The angles of an equilateral triangle are all equal.
3)The sum of exterior angles of a triangle is 360 degrees.
4)The sum of interior angles of a triangle is 180 degrees.