Question

An isosceles triangle has angle measures 55°, 55°, and 70°. The side across from the 80° angle is 10 inches long. How long are the other sides? A. 8.72 inches B. 11.47 inches C. 10 inches D. 8.19 inches

Answer 1

Answer: it is D 8.19 inches

Step-by-step explanation:

Answer 2

Answer:

Measure of three angles of Isosceles Triangle are ,55°, 55°, and 70°.

Length of side across 80° angle = 10 inches

We will use Sine Rule Here, which states that

$\frac{a}{sinA}=\frac{b}{sinB}=\frac{c}{sinC}\\\\ \frac{10}{sin 70}=\frac{b}{sin 55}=\frac{c}{sin 55}\\\\ \frac{10}{0.974}=\frac{b}{0.8191}=\frac{c}{0.82}\\\\ b=\frac{8.2}{0.974}=8.418\\\\c=8.418$

Length of other sides = 8.41 inches

Option D: 8.19 inches