Question

An isosceles triangle has 2 sides equal to 0.96 inches and the measure of the angle between them is 104.5 degrees. What is the measure of the third side? Please show work.

Answer 1

`0.96 sqrt 2 sqrt{1 - cos 104.5º}`

Explanation:

`AB = c = AC = b = 0.96, angle A = 104.5º`

Let's use "cos rule"
`a^2 = b^2 + c^2 - 2bc cos A`

`BC^2 = 0.96^2 + 0.96^2 - 2 * 0.96^2 cos 104.5º`

`BC = 0.96 sqrt{1 + 1 -2 cos 104.5º}`