158k views
1 vote
A triangle has side lengths of 18 in., 22 in., and 29 in. Is the triangle acute, obtuse, or right?

Acute
Obtuse
Right
None of the above

1 Answer

10 votes

Answer: Obtuse

========================================================

Step-by-step explanation:

We have a triangle with these side lengths

  • a = 18
  • b = 22
  • c = 29

Computing a^2+b^2 gets us

a^2+b^2 = 18^2+22^2 = 808

Compare this to c^2

c^2 = 29^2 = 841

Because 808 < 841, this means a^2+b^2 < c^2

-------------------

We have three cases:

  • If a^2+b^2 > c^2, then the triangle is acute
  • If a^2+b^2 = c^2, then we have a right triangle
  • If a^2+b^2 < c^2, then the triangle is obtuse

For more information, check out the converse of the Pythagorean Theorem.

User AndyRyan
by
5.3k points