MM
Mashaal Masha
Dec 18, 2022
Choose the correct options for the following questions.
In $\triangleABC$ if $\beta=90^{\circ}$, then according to law of cosine the value of the square of the side b is defined as:
Difficulty: Easy
A:
$b^{2}=a^{2}+b^{2}-2ab$
B:
$b^{2}=b^{2}+b^{2}-2bc\cos\beta$
C:
$b^{2}=a^{2}+c^{2}$
D:
$b^{2}=a^{2}+c^{2}+2ac\cos\beta$
In $\triangleABC$ if$\alpha=90^{\circ}$ then according to law of cosine the value of the square of the side a is defined as
Difficulty: Easy
A:
$a^{2}=b^{2}+c^{2}$
B:
$a^{2}=a^{2}+c^{2}+2ac$
C:
$a^{2}=b^{2}+c^{2}+2bc\cos\alpha$
D:
$a^{2}=b^{2}+c^{2}-2bc\cos\alpha$
If $\alpha, \beta\:and\:\gamma$ are the measures of the angles of a triangle, and a, b and c are the lengths of sides opposite these angles then according be law of cosine, the value of $cosine\gamma$ is defined as:
Difficulty: Easy
A:
$\cos\gamma=\frac{a^{2}+c^{2}-b^{2}}{2ac}$
B:
$\cos\gamma=\frac{a^{2}+c^{2}-b^{2}}{2ac}$
C:
$\cos\gamma=\frac{a^{2}+c^{2}+2ab\cos\gamma}{b^{2}}$
D:
$\cos\gamma=\frac{b^{2}+c^{2}-a^{2}}{2bc}$
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