Isosceles Triangle Practice

Question Icon

Question 1

Which of the following triangles are isosceles triangles?

identify all the isosceles triangles

Answer

Answer Icon

Select and check your answer...

A. I & III
B. II & III
C. III & IV
D. I & IV

Step by Step Solution

  • Lesson Icon

    Step 1

    For triangle I, it has two sides of equal length (8.0ft). Hence, it is an isosceles triangle.

    Triangle IV is an isosceles triangle
  • Lesson Icon

    Step 2

    As for triangle II, it is an isosceles triangle since its base angles are the same.

    Triangle IV is an isosceles triangle
  • Lesson Icon

    Step 3

    As for triangle III, all the sides have different lengths. Therefore, it is not an isosceles triangle.

    Triangle IV is not an isosceles triangle
  • Lesson Icon

    Step 4

    For triangle IV, all the internal angles are different. This means that all the sides of the triangle do not have the same length. Hence, this is not an isosceles triangle.

    Triangle IV is not an isosceles triangle
  • Lesson Icon

    Step 5

    Clearly, only triangle I and II are isosceles triangles. Therefore, the answer is A.