Answer:
Step-by-step explanation:-
15)
ABCD is quadrilateral
∠MBC+∠ABC=180°
∠ABC = [tex]\tt 180-71=109^o[/tex]
The sum of all angles of quadrilateral = 360°
[tex]\tt 10x+6+12x-2+8x-1+109=360^o[/tex]
[tex]\tt 31x+112=360[/tex]
[tex]\tt 31x+112-112=360-112[/tex] ( Subtract 112 from both sides)
[tex]\tt 31x=248[/tex] (Simplify)
[tex]\tt \cfrac{31x}{31}=\cfrac{248}{31}[/tex] (Divide both sides by 21)
[tex]\tt x=8[/tex]
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16) Find m∠v
The polygon has 6 sides
Sum of angles:- (6-2)=180= 720°
so,
[tex]\tt 90+9x-19+111+5x+8+128+7x+3=720[/tex]
[tex]\tt 2x+321=720[/tex]
[tex]\tt 21x+321-321=720-321[/tex] ( Subtract 321 from both sides)
[tex]\tt 21x=399[/tex] (Simplify)
[tex]\tt \cfrac{21x}{21}=\cfrac{399}{21}[/tex] ( Divide both sides by 21)
[tex]\tt x=19[/tex]
Therefore, m∠v=19
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