Step 1: Draw a line segment BC of 11 cm.
Step 2: From point B , draw an angle of 30 degrees.from point C , draw an angle of 90 degrees.
Step 3: Draw the angle bisectors of B and C. They intersect at a point A.
Step 4: Draw line bisector of XA and AY respectively. These two line bisectors intersect XY at point B and C
Step 5: Join X to Y and Z to Y.
Step: Triangle XYZ is the required triangle.