tail: 4.5x5/2=11.25, 4.5x3/2=6.75, 11.25+6.75=18
top fin: 3x2.25/2=3.375, 3x0.75/2=1.125, 3.375+1.125=4.5
bottom fin: 1x1/2= 0.5, 1x0.5/2=0.25, 0.5+0.25=0.75
nose: 4.5x2=9
between tail and body: 2.5x2=5
corners on body: 1.5x0.5/2x4=1.5
top and bottom on body: 0.5x5x2=5
body: 1.5x2+5=8, 2x2=4, 4x8=32
total: 18+4.5+0.75+9+5+1.5+5+32=75.75
total area of khianna's fish is 75.75 cm.
hope this helps