​Pls answer in full steps and illustrated diagrams and pls don't give any links-

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Dear Student,
Please find below the solution to the asked query:

$$\begin{gathered} \left(\mathrm{a}\right) \\ \mathrm{Yes}, \mathrm{it} \mathrm{is} \mathrm{possible} \mathrm{to} \mathrm{construct} \mathrm{triangle} \mathrm{ABC} \mathrm{if} \mathrm{perimeter} \mathrm{of} \mathrm{the} \mathrm{triangle} \mathrm{is} 11 \mathrm{cm}, \\ \mathrm{base} \mathrm{angles} \mathrm{are} \angle \mathrm{A}=60° \mathrm{and} \angle \mathrm{B}=70° \\ \left(\mathrm{b}\right) \mathrm{No}, \mathrm{it} \mathrm{is} \mathrm{not} \mathrm{possible} \mathrm{to} \mathrm{construct} \mathrm{triangle} \mathrm{EFG} , \mathrm{if} \mathrm{EF} + \mathrm{FG} + \mathrm{GE} = 11 \mathrm{cm} \\ \mathrm{because} \angle \mathrm{E}+\angle \mathrm{F}=105°+90°=195° \mathrm{as} \mathrm{sum} \mathrm{of} \mathrm{all} \mathrm{angles} \mathrm{is} 180°. \\ \left(\mathrm{c}\right) \mathrm{Yes}, \mathrm{it} \mathrm{is} \mathrm{possible} \mathrm{to} \mathrm{construct} \mathrm{triangle} \mathrm{XYZ} \mathrm{if} \mathrm{perimeter} \mathrm{is} 12.5 \mathrm{cm}, \mathrm{a} \\ \angle \mathrm{X}=75° \mathrm{and} \angle \mathrm{Y}=30° \mathrm{as} \mathrm{sum} \mathrm{is} \mathrm{less} \mathrm{than} 180° \end{gathered}$$

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