Question

construct the triangle ABC which is AB=5cm ,BC=8cm,CA=4cm

Answer 1

DRAW A LINE SEGEMENT B AND C OF 8 CM 
MEASURE 5 CM ON COMPASS AND KEEP THE POINTER AT B AND MAKE AN ARC
NOW AGAIN TAKE COMPASS AND MEASURE 4 CM ON IT AND DRAW AN ARC THAT CUTS OTHER ARC
NAME THAT POINT AS A WHERE BOTH ARC MEETS JOIN A WITH B AND C 
THEREFORE ABC IS REQUIRED TRIANGLE