Question
We have learnt that if two triangles are equiangular then their sides are in proportion. What do you think if two quadrilaterals are equiangular? Are their sides in proportion? Draw different figures and verify. Verify the same for other polygons.

Answer

If two quadrilaterals are equiangular then their sides will not necessarily be in proportion.
Case 1: The two quadrilaterals are of the same type.

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Consider squares ABCD and PQRS.
∠A = ∠P, ∠B = ∠Q, ∠C = ∠R, ∠D = ∠S
$\frac{ AB }{ PQ }=\frac{ BC }{ QR }=\frac{ CD }{ RS }=\frac{ AD }{ PS }$
Case 2: The two quadrilaterals are of different types.

Image
Consider square ABCD and rectangle STUV.
∠A = ∠S, ∠B = ∠T, ∠C = ∠U, ∠D = ∠V
Now, $\frac{ AB }{ ST }=\frac{ CD }{ UV }$ and $\frac{ BC }{ TU }=\frac{ AD }{ SV }$ But $\frac{ AB }{ ST } \neq \frac{ BC }{ TU }$

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