题干
The coordinates of the three points A．B．C on the plane are (﹣5，﹣5)，(﹣2，﹣1)and(﹣1，﹣2)respectively，the triangle ABC is( )
(英汉小词典：right直角的；isosceles等腰的；equilateral等边的；obtuse钝角的)
A. a right trisngle B. an isosceles triangle
(英汉小词典：right直角的；isosceles等腰的；equilateral等边的；obtuse钝角的)
A. a right trisngle B. an isosceles triangle
| A．an equilateral triangle | B．an obtuse triangle |
答案(点此获取答案解析）
