Question

If one angle of a triangle is equal to the sum of other two, show that the triangle is a right-angled triangle.​

Answer 1

So, in triangle ABC,angleA + angleC= angleB …………(1)Now, in triangleangle A +angle B+ angle C =180°= angle B + ( angleA + angleC) =180°= angleB + angleB =180°…………..from(1)=2 angleB = 180°= angle B = 180°/2=angleB= 90°So, one angle of triangleABC is 90° or if one angle of triangle is 90° this triangle is known as right angled triangle.So, it is right angled triangle

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