Answer:
[tex]\text{In all of these questions, we will add the lengths of boundary of the shapes, }\\\text{and equate them with their given perimeter.}[/tex]
[tex]\text{a. }x+7+5+2=17\\\text{or, }x+14=17\\\text{or, }x=3[/tex]
[tex]\text{b. (The same symbol on the sides represents that the side lengths are equal.)}\\\therefore\ x+x+5.3=22.9\\\text{or, }2x=17.6\\\text{or, }x=8.8[/tex]
[tex]\text{c. }2x+2x+2x+2x=0.072\\\text{or, }4x=0.072\\\text{or, }x=0.018[/tex]
[tex]\text{d. }2.8+2.8+2x+2x=16.2\\\text{or, }4x=10.6\\\text{or, }x=2.65[/tex]
[tex]\text{e. }3x+11.61+3.72+7.89+3.72=46.44\\\text{or, }3x+26.94=46.44\\\text{or, }3x=19.5\\\text{or, }x=6.5[/tex]
[tex]\text{f. }x+1.5x+2x=10.8\\\text{or, }4.5x=10.8\\\text{or, }x=2.4[/tex]
