Construct a trian

Step1: construct segment YZ which is 4.5 cm and draw a ray at 60° from point Y

Step2: using a scale or compass mark a point D on the ray at 7.5 cm from Y and join ZD

Now we have to construct the perpendicular bisector of ZD

Step3: take any distance approximately by observation in compass greater than half of ZD. Keep the needle of the compass on point D and mark arcs left and right of ZD and keeping the same distance in compass keep the needle on point Z and cut the arcs as shown and join both the intersected arcs. Thus we have drawn the perpendicular bisector of ZD. Mark the intersection point of the perpendicular bisector of ZD and YD as point X join XZ and ΔXYZ is ready