This simple outdoor sofa was made from rough wood and they are not a standard normal size,in making this there are four major steps
1 making the legs
2 connecting the two sets of legs
3 making the back sit rest
4 shaping and sanding
, I also wrote all the measurement on each pieces check the photos on step 4.

Supplies

Materials
1 2/2 rough wood ( I made this sofa out of all available used wood, wood glue, and nails.
Tools
1saw ,2 pincer,3 chisel(this is not a regular chisel i make this of a flattened nail tip),4 hammer 5 tape (mm) 6 glove.
2

Step 1: MAKING THE LEGS

I used 2/2 lumber for the four legs as well as the arm, I started by cutting out 60.2mm for the front legs of both side 50.3 for backs, 40.3 for arms and 40.7 for the middles ( all in milli meters), next I measure 10mm from the base of the 2 legs (front&back)which will be starting point for connecting the middle rest ,then I put all the four pieces together by making mortise$tenon joint with my chisel (flating nail )and securing them with1/2 inches of nail ,I first cut the head of the nails with pincer to sink well.
1 front legs = 60.2mm
2 back legs= 50.3mm
3 arm rest = 40.3mm
4 middle rest= 40.7mm.

Step 2: CONNECTING THE 2 SETS OF LEG UP

I connect the two legs with a 130.3mm long flat 1/3 lumber by Mortise$ tenon joint method, gum and nails ,I measure 10mm from the base of the leg I will be starting my connecting from that mark, there i will be connecting the two legs from one end to other, I also cut out additional four 130.3mm for the flat sitting platform I secure them with 3inches nails.now the sofa is taking shape, the two legs has been connected with the flat sitting area but there is something missing ,the back rest ,this will be attached as it is made separately.now let's make

Step 3: MAKING THE BACK SIT REST

The back sit rest has a ladder like structure I made it separate and attached to the legs, I cut out two 1/3 of 120.3 flat lumber for up&down , two 2/2 50.6 for the sides and eight 1/3 30.1 flat lumber s for the midles with 0.9 mm spacing ,i first connected all the eight pieces by Mortise and tenon method with 0.9 mm spacing and securing them with 1/2 inches nail next i connect the two 50.6 lumber sides with 3inches nails ,now the back rest is ready i attached it to the legs with long nails, the position of the rest whether you like it forward or backward depends on you.i also secure the under of the sit with a 2/2 at the middle underneath
Measurement.
Up&down=120.3mm
Sides=50.6mm
Middles=30.1mm(0.9 spacing when connecting)

Step 4: SHAPING AND SANDING

I filled all the holes with mixture of glue and wood shavingsa and sand paper it to give it a nice look , it is still work in progress but I will update you when I sand it and paint , however I wrote all the measurement on each piece as seen above, thank you