Question

construct an isosceles triangle with length of each equal side is 4.5 cm and base is 5.8 centimetre

Answer 1

take a ruler and draw a 5.8 cm line
use ur rounder to make a distance of 4.5 cm and make arcs from both the sides of the 5.8 cm line 
u will get  a point of intersection from both the arcs
join the points 
and its done!

Answer 2

The length of the two equal sides will be 4.5 cm and the third side will be 5.8cm