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23 votes
Help please
im pretty sure this is called angle sum theory but I could be wrong

Help please im pretty sure this is called angle sum theory but I could be wrong-example-1
User Koffiman
by
3.0k points

2 Answers

8 votes

Answer:

x= 180°-115°

= 65° ( adjacent angles in a straight line)

y= 180°-90°-65°

= 25° ( angle sum of a triangle)

User Anthony Granger
by
4.0k points
9 votes

y = 25

Explanation:

=> 115 = y + 90 {exterior angle of triangle is equal to the sum of its opposite two interior angles}

=> 115 = y + 90

=> 115-90 =y

=> 115 = y + 90

=> 115-90 =y

=> y = 25

User Ryan Erwin
by
4.4k points