Trigonometric Equations Question 283
Question: In a $ \Delta ABC, $ if $ b=20,c=21 $ and $ \sin A=3/5 $ , then $ a= $
[EAMCET 2003]
Options:
A) 12
B) 13
C) 14
D) 15
Show Answer
Answer:
Correct Answer: B
Solution:
- $ a^{2}=b^{2}+c^{2}-2bc\cos A $
Þ $ a^{2} $ $ ={{(20)}^{2}}+{{(21)}^{2}}-2.20.21.\frac{4}{5}=169 $
Þ $ a=13. $
BETA
