Question

Triangle E D F has sides that are of varying lengths. Side E D has a length of 4 and side E F has a length of 9.
Which statements about the diagram are true? Select three options.

D E + E F greater-than D F
Triangle D E F is an isosceles triangle.
5 less-than D F less-than 13
D E + D F less-than E F
Triangle D E F is a scalene triangle.

Answer 1

The true statements are:

- D E + E F > D F (4 + 9 = 13 > DF by the triangle inequality)
- 5 < D F < 13 (|9 − 4| = 5 < DF < 9 + 4 = 13)
- Triangle D E F is a scalene triangle (the problem states the sides are varying lengths, so no two sides are equal)

The isosceles statement and D E + D F < E F are false.