If the two triangles are congruent, then you can conclude that they have 3 angles in common, or that they are identical or that you could use rigid motions (dilations, translations or reflections) to align them together.
1.) Find the area of the circle at the top ( A= pi x radius squared ) 2.) radius is 5.55 (half of 11.1) 3.) A= pi x 5.55 squared 4.) area of circle =96.77 5.) multiply area of circle(96.77) by height (20) 6.) answer = 1935.38