Gujarat BoardEnglish MediumSTD 7MATHSLines and Angles2 Marks
Question
Find the angle, which is equal to its complement.
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Answer
Let the angle be $x$. Therefore, its complement be $90^{\circ}-x$. Since, the angle is equal to its complement. $ x=90^{\circ}-x $ On transposing $x^{\circ}$ from RHS to LHS, we get $ \begin{array}{rlrl} x+x=90^{\circ} \\ \Rightarrow 2 x =90^{\circ} \end{array} $ On dividing both sides by 2 , we get $ \begin{array}{rlrl} \frac{2 x}{2}=\frac{90^{\circ}}{2} \\ \Rightarrow x=45^{\circ} \end{array} $ Hence, the required angle is $45^{\circ}$.
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