(2) AE+ED 1= 1, ED 1÷AE = 5, and the sum of ED 1= (root number 5 and 1) is obtained. So ED is also equal to 1 of the sum of (root 5 and 1), so the area of triangle CED 1 is equal to 1 of the sum of triangle EDC =DC×DE÷2= (root 5 and 1). Namely: 1/4 (the difference between the root number 5 and 1)