Two long strips of paper are each $2$ inches wide, and they overlap so that the angle between the strips is $20^{\circ}$. What is the number of square inches in the area of the parallelogram formed by the overlap?
We can slpit the paralllelogram in half such that we form two isosceles triangles with the apex angle = 160°
The sides are all equal and we can find the length of one (= s) as
2 / sin 20° = s / sin 90
s = 2 /sin 20°
Area =
s^2 * sin (160°) =
( 2 / sin 20°)^2 * sin (160°) = 11.7 in^2