AB is the diameter of a circle with centre O. C and D are two points on the circle on either side of AB, such that ∠ CAB = 52° and ∠ ABD = 47° What is the difference (in degrees) between the measures of ∠ CAD and ∠ CBD ? |
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10 |
According to the concept, \(\angle\)ACB = \(\angle\)ADB = \({90}^\circ\) So, \(\angle\)CBA = \({180}^\circ\) - (\({90}^\circ\) + \({52}^\circ\)) ⇒ \({180}^\circ\) - \({142}^\circ\) ⇒ \({38}^\circ\) Similarly, ⇒ \(\angle\)BAD = \({180}^\circ\) - (\({90}^\circ\) + \({47}^\circ\)) ⇒ \({180}^\circ\) - \({137}^\circ\) ⇒ \({43}^\circ\) So, \(\angle\)CAD = \({52}^\circ\) + \({43}^\circ\) ⇒ \({95}^\circ\) \(\angle\)CBD = \({38}^\circ\) + \({47}^\circ\) ⇒ \({85}^\circ\) Now, \(\angle\)CAD - \(\angle\)CBD = \({95}^\circ\) - \({85}^\circ\) ⇒ \({10}^\circ\) Therefore, the difference between the measures of ∠ CAD and ∠ CBD is \({10}^\circ\) |