Question

lesson 7: triangles
classifying triangles by side length
an isosceles triangle has ______
a. all three sides the same length
b. no equal angles
c. no sides equal in length
d. two sides equal in length
check answer

Explanation:

To solve this, we recall the definition of an isosceles triangle. An isosceles triangle is defined as a triangle that has two sides of equal length (and also two equal angles, but the question is about side lengths). Let's analyze each option:

• Option a: A triangle with all three sides the same length is an equilateral triangle, not isosceles.
• Option b: The question is about side lengths, and "no equal angles" is not related to the side - length definition of an isosceles triangle (also, an isosceles triangle does have equal angles opposite the equal sides).
• Option c: A triangle with no sides equal in length is a scalene triangle.
• Option d: Matches the definition of an isosceles triangle (two sides equal in length).

Answer:

d. two sides equal in length