Question

If angles of a triangle are (x - 40), (x - 20) and ( x/2 - 10 ).Find the value of x.
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Answer 1

The sum of angles of triangle is 180°.

So, (x-40)+(x-20)+(x/2-10)=180°

x-40+x-20+{(x-20)/2}=180

x+x+40-20+(x-20)/2=180

2x+20+(x-20)/2=180

(4x+40+x-20)/2=180

(4x+x+40-20)/2=180

(5x+20)/2=180

5x+20=180×2

5x+20=360

5x=360-20

5x=340

x=340/5

x=68°