Which of the following best describes the line of symmetry? A. The line that is perpendicular to the design
B. The line that is parallel to the design
C. The line that divides the design into two similar parts
D. The line that divides the design into two congruent parts

C the line that divides the design into two similar parts

A the line that is perpendicular to the disign

25/4

step-by-step explanation:

call segment cd's length x. because dc and ab are parallel, angle acd and cab, so triangles adc and abc are similar and we can set up the equation x / ac = ac / ab, or x / 5 = 5 / 4 and x = 25/4.