[tex] \huge \tt \color{pink}{A}\color{blue}{n}\color{red}{s}\color{green}{w}\color{grey}{e}\color{purple}{r }[/tex]
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❒ Given ❒
- ➣ Mid point of a circle
- ➣ Tangent AB
- ➣ Angle "o" of 42⁰
- ➣ Angle "A" of 90⁰ (cuz it is the perpendicular of traingle given in circle)
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❒ Note ❒
- ➣here tangent AB with point O (mid point of circle) forming a traingle
- ➣we have to find "y" in the given figure (angle B)
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❒ Concept used ❒
- ➣The sum of interior angles of traingle is of 180⁰
- ➣to find the missing angle ( y ) we will use this theorem
- ➣this Concept is also know as Sum theorem
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❒ Assumption ❒
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❒ Let's solve ❒
[tex] \large \pmb{➪ \: } \rm \pink{ \angle \: OAB+\angle \:ABO+\angle \:BOA = 180 \degree}[/tex]
- ➣let's substitute value now .....
[tex] \pmb{➪ \: 90 + y +42 = 180 } \\ \pmb{➪ \:132 + y = 180 \: \: \: \: \: \: \: \: }\\ \pmb{➪ \:y = 180 - 132 \: \: \: \: \: \: \: \: }\\ \pmb{➪ \:y = 48 \degree \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: }[/tex]
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Hence the size of angle is
[tex] \large \boxed{✥\underline{ \boxed{ \sf{y = 48 \degree \: \pmb{\green{✓}} }}}✥}[/tex]
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Hope it helps !