Question

in fig. if angle A=(2x+10)°,angleB=(x+20)°,angleC=(y-10)°,find the values of x and y.​

Answer 1

sum of three angles is 180°.

A+B+C=180

2x+10+x+20+y-10=180

3x-y+20=180

3x-y= 160

Answer 2

A+B+C = 180
[angle sum property]
=> 2x + 10 + x +20 + y -10 = 180
=> 3x + y = 180-20
=> 3x + y = 160
=> x = (160-y)/3
=> y = 160-3x