Isosceles triangle characteristic:

Isosceles triangle characteristic:

• A. The triangle cannot be acute.
• B. Two sides have the same length, two angles have the same measure.
• C. All three angles are different.
• D. Two angles are unequal.

Answer: (B)

In an isosceles triangle, two sides are equal in length. When two sides are the same, the angles opposite those sides are equal as well, so two angles have the same measure. That combination—two equal sides and two equal angles—is the defining trait here. It’s also possible for an isosceles triangle to be acute, right, or obtuse, so the shape isn’t fixed to one type of angle. The other statements don’t fit: you can have an isosceles triangle with two equal angles, and even an equilateral triangle (all three sides equal) is a special case of isosceles that still has two equal angles. You cannot have all three angles different, nor can two angles be unequal in a true isosceles triangle.

In an isosceles triangle, two sides are equal in length. When two sides are the same, the angles opposite those sides are equal as well, so two angles have the same measure. That combination—two equal sides and two equal angles—is the defining trait here. It’s also possible for an isosceles triangle to be acute, right, or obtuse, so the shape isn’t fixed to one type of angle. The other statements don’t fit: you can have an isosceles triangle with two equal angles, and even an equilateral triangle (all three sides equal) is a special case of isosceles that still has two equal angles. You cannot have all three angles different, nor can two angles be unequal in a true isosceles triangle.