An art easel is in the shape of a triangle with its three slant legs that do not join at the apex or the top. The bottom is broad, giving the glimpse of a triangle.
Given is :
Serena has an art easel with sides of equal lengths.
She opened the easel and placed it on her desk.
So, the shape will look like equilateral triangles.
And obtuse angles or triangles are formed by the easel and the desk according to its angles. This is because we can assume the desk to be a straight line, and the easel legs make an obtuse angle on that line. Thus, obtuse angles are formed.