Answer :
lets say that you had a triangle that had an area of 64, each side being 4 (4X4X4=64) then you cut each side in half 2X2X2 the percentage decrease would be 87%
Please find attached photograph for your answer.
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![View image Аноним](https://us-static.z-dn.net/files/dd3/fbad259fac1313fa8087ca4aa7957d7f.jpg)