Question

Rhombus A B C D is shown. Lines are drawn from point A to point C and from point D to point B and intersect at point E. All sides are congruent.
The area of rhombus ABCD is 72 square units. EC = 8 units and DB = x – 1.

What is the value of x?
9
10
14
16

Answer 1

Answer: If answer above is correct then D on EDGE

Step-by-step explanation:

Because ^^^ said so :)

Answer 2

Area of rhombus = 1/2 * diagonal * diagonal

72 = 1/2 * AC * BD

Diagonals bisect each other in a rhombus so if EC is 8 then AC is 16

72 = 1/2 * 16 * x - 1
72 = 8(x-1)
9 = x-1
X = 10

Check
72 = 1/2 * 16 * 10-1
72 = 1/2 * 16 * 9
72 = 8 * 9
72=72