Final answer:
All triangles have three sides, equilateral triangles have equal angles, right-angled triangles have one angle measuring 90 degrees, and isosceles triangles have all sides equal.
Step-by-step explanation:
A) All triangles have three sides
B) Equilateral triangles have equal angles
C) Right-angled triangles have one angle measuring 90 degrees
D) Isosceles triangles have all sides equal
All of the statements A, B, C, and D are true about triangles:
- All triangles have three sides. This is a fundamental characteristic of a triangle.
- Equilateral triangles have equal angles. In an equilateral triangle, all three angles are equal and each angle measures 60 degrees.
- Right-angled triangles have one angle measuring 90 degrees. In a right-angled triangle, one of the angles is a right angle, which measures 90 degrees.
- Isosceles triangles have all sides equal. In an isosceles triangle, two sides are equal in length.