Question

    <p><p>The length of sides of a

    square is twice the radius of a circle and perimeter of a rectangle is half the perimeter of the square. If the sum of length and breadth of rectangle is 16 cm, then find the area of the circle (in cm<sup>2</sup>). [Take π = 2]</p></p>
    A 200 sq.cm Correct Answer Incorrect Answer
    B 128 sq.cm Correct Answer Incorrect Answer
    C 115 sq.cm Correct Answer Incorrect Answer
    D 120 sq.cm Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    <p>&lt;p&gt;Let the length of a square be &amp;lsquo;a&amp;rsquo;.&lt;/p&gt; &lt;p&gt;And the radius of a circle be &amp;lsquo;r&amp;rsquo;.&lt;/p&gt; &lt;p&gt;Now, a = 2r ----- (i)&lt;/p&gt; &lt;p&gt;Perimeter of the rectangle = 1/2 &amp;times; 4a = 2a&lt;/p&gt; &lt;p&gt;=&amp;gt; 2(l + b) = 2a&lt;/p&gt; &lt;p&gt;=&amp;gt; 2 &amp;times; 16 = 2a&lt;/p&gt; &lt;p&gt;=&amp;gt; a = 16 cm&lt;/p&gt; &lt;p&gt;Putting value of &amp;lsquo;a&amp;rsquo; in (i) we get,&lt;/p&gt; &lt;p&gt;Radius = r = 16/2 = 8 cm&lt;/p&gt; &lt;p&gt;Area of the circle = &amp;pi;r&lt;sup&gt;2&lt;/sup&gt;&amp;nbsp;= 2 &amp;times; 8 &amp;times; 8 = 128 cm&lt;sup&gt;2&lt;/sup&gt;.&lt;/p&gt;</p>

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