Trigonometric Equations Question 124
Question: If the sides of a triangle are $ 3,\ 5,\ 7, $ then
[MP PET 1996]
Options:
A) All its angles are acute
B) One angle is obtuse
C) Triangle is right angled
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
- $ \cos C=\frac{3^{2}+5^{2}-7^{2}}{2\times 3\times 5}\Rightarrow C=120{}^\circ $ .
BETA
