Steps of construction:
i. Draw seg AD of 11.6 cm.
ii. Draw ray AX such that ∠DAX is an acute angle.
iii. Locate points A1 , A2 and A3 on ray AX such that AA1 = A1 A2 = A2 A3
iv. Join A1 D.
v. Through A1 , A2 draw lines parallel to A D intersecting AD at B and C, wherein AB = 11.6/3 cm