plz help for brainliest

Answer:
Yes it is an isosceles triangle
Step-by-step explanation:
We just need to see if the distance between two points is the same as the distance with two others
Distance between AB = (4 -(-1))² + (7 - 2)² = c²
5² + 5² = c²
25 + 25 = c²
c = √50
Distance between AC = (11-(-1))² + (8 - 2)² = c²
12² + 6² = c²
144 + 36 = c²
180 = c²
c = √180
Distance between CB = (11-4)² + (8 - 7)² = c²
7² + 1² = c²
49 + 1 = c²
50 = c²
c = √50
Hence, this is an isosceles triangle because AB and CB are congruent in length.
-Chetan K
We need to verify if any of two sides are equal then it is an isosceles triangle.
Refer to the attachment now