Question

The sticks of the same length are used to form a triangle as shown below. If 87 such sticks are used then how many triangles can be formed?

Answer 1

After making a triangle with 3 stick then in continuous it needs only 2 stick to form the triangle

Then 87-3=84 triangle is there so 842 =  42 sticks are used but 1 is already formed by 3 stick so it is 42+1=43

Or Simply use this formula:-

2n+1=87

2n=87-1

2n=86

n=43.

Hence 43 no of triangle can be made by the 87 sticks.

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