Steps of construction:
Construct a line segment PQ = 10.4cm
Draw a 45o and bisect it to obtain ∠NPQ
Draw a 120o and bisect it to obtain ∠MQP
Rays PN and QM intersect at the point A
Draw the perpendicular bisectors of PA and QA which intersects PQ at the points B and C
Join the point AB and AC
Therefore, △ ABC is the required triangle.