3 years ago

The sides of an isosceles triangle are 5, 5, and 7. Find the measure of the vertex angle to the nearest degree.

2 answers:

8 0

You can use the cosine law with the formula:
a^2 = b^2 + c^2 - 2*b*c*cosA
With a = 5, b = 5, c = 7,
7^2 = 5^2 + 5^2 - 2*5*7*cosA
49 = 25 + 25 - 70*cosA
70*cosA = 25 + 25 - 49
70*cosA = 1
cosA = 1/70
A = arccos (1/70) = 89.18 deg = 89 deg

olga2289 [7]3 years ago

7 0

Answerino:

89 degrees

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Find the value of the variable that results in congruent triangles. Explain. SAS (Side, Angle, Side) or ASA (Angle, Side, Angle)

Mamont248 [21]

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