Section 9.4 a-triangle inequality theorem
triangle inequality theorem
than the
the sum of the lengths of any two sides of a triangle is
length of the third side.
example: determine if the given side lengths form a triangle.
a) 4, 5, 10
b) 4, 5,9
c) 4,5,7
practice:
the triangle inequality theorem states that the sum of the lengths of any two sides of a
triangle is greater than the length of the third side. using this theorem, answer the following
questions.
1) if two sides of a triangle are 1 and 3, the third side may be:
(a) 5
(b) 2
(c) 3
(d) 4
2) if the lengths of two sides of a triangle are 5 and 7, the length of the third side may not be:
(a) 12
(b) 7
(d) 5
(c) 3