Question

the angles of triangle are x, y and 40 degree. The difference between the two angles x & y is 30 degree. Find x & y

Answer 1

x+y+40=180.  (Angle sum property of triangle)

x+y=180-40

x+y=140 ————————————— equation #1

Given that the difference between x and y is 30 degrees

x-y=30 —————————————— equation #2

Addind equations #1 & #2 implies

(x+y)+(x-y)=140+30

2x=170

x=170/2

x=85 degrees

x+y=140

85+y=140

y=140-85

y=55 degrees

Answer 2

X - y = 30 --------------------eqn 1

X + y + 40 = 80 ( since sum of angles of a triangle = 80 )

X + y = 140 --------------------eqn 2 ( variables on one side constants on one side )

From eqn 1 and 2

By elimination method we get

X = 85 and Y = 55

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