A triangle has side lengths of 13 cm and 6 cm. Which could be the value of the third side, 21 cm or 17 cm?
1 answer:
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Answer:
The answer to your question is letter D
Step-by-step explanation:
We know that the sum of the internal angles in a triangle equals 180°.
So, B = 30°, C = 90° and A = ?
A + B + C = 180°
Substitution
A + 30 + 90 = 180
Solve for A
A = 180 - 30 - 90
A = 180 - 120
A = 60°
To find "b". use the trigonometric function sine
sin B =
sin B x hypotenuse = Opposite side
Opposite side = sin 30 x 10
Opposite side = 0.5 x 10
Opposite side = b = 5.0
To find "a" use the trigonometric function cosine
Cos A = adjacent side / hypotenuse
Adjacent side = a = cos A x hypotenuse
Adjacent side = a = cos 60 x 10
a = 0.866 x 10
a = 8.66