# Math Help - circle questions 3

1. ## circle questions 3

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2. Originally Posted by dgenerationx2
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Hello dgen,

(20) $m\angle AOB=70$

The angle adjacent to $\angle AOB$ is $\angle COB$.

$m\angle COB=110^{\circ}$ because these two angles make up a linear pair and are supplementary.

$\angle COB$ is a central angle and has the same measure as its intercepted arc.

Therefore, $m\widehat{CB}=110^{\circ}$

(24) The measure of an inscribed angle in a circle is one-half the measure of its intercepted arc.

$3x+7=\frac{1}{2}(134)$

$3x+7=67$

$3x=60$

$x=20$

(26) $m\widehat{XY}=40^{\circ}$

$m\widehat{WX}=180-40=140^{\circ}$