Question

question 19 of 40 a triangle with sides of lengths 10, 18, and 21 is a right triangle. a. true b. false

Explanation:

Step1: Recall Pythagorean theorem

For a right - triangle, \(a^{2}+b^{2}=c^{2}\), where \(c\) is the longest side.

Step2: Identify sides

Let \(a = 10\), \(b = 18\), \(c = 21\).

Step3: Calculate \(a^{2}+b^{2}\)

\(a^{2}+b^{2}=10^{2}+18^{2}=100 + 324=424\).

Step4: Calculate \(c^{2}\)

\(c^{2}=21^{2}=441\).

Step5: Compare

Since \(424
eq441\), it's not a right - triangle.

Answer:

B. False