Answer:
The value of Cos(60°) is ½
Step-by-step explanation:
B)as we know
b²=a²+c²-2ac.cos(b)
b=√5²+8²-2.5.8×cos(60°)
b=√25+64-80×½
b=√25+64-40
b=√89-40
b=√49
b=7 (proven)
We have to Prove b=7.
A plane figure with three straight sides and three angles.
As we know,
b²=a²+c²-2ac.cos(b)
b=√5²+8²-2.5.8×cos(60°)
b=√25+64-80×½
b=√25+64-40
b=√89-40
b=√49
b=7 (proven)
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