Which of the following are congruent triangles reflection

Aswimming pool is a rectangle with semicircles on the end. the rectangle is 12 meters wide and 30 meters long. the diameter and width of the swimming pool are equal. sketch and label an overhead diagram of the swimming pool. find the area of the swimming pool floor.

X+ y = 5 ; x - y =3 solve using linear combination

Math it's appreciated. (picture provided)