Scalene triangle → Different length, therefore no congurent sides.
Isosceles triangle → Same length, therefore it has two congurent sides.
Equilateral triangle → All length are comparable, it has three congurent sides.
Right triangle → Measures 90°, in some cases, it has two congurent sides.
Congurent defination → Same shape and same size.
Answer → C) Isosceles triangle.