Steps of construction
Step I Draw a line AB = 4.5 cm
Step II Construct a right angle (90∘) at point B, i.e. ∠ABY=90∘.
Step III From point B cut an arc 4.5 cm on BY at C.
Step IV Join C to A.
Hence, ΔABC is the required triangle having AB = AC = 4.5 cm.