Если квадрат большей стороны равен сумме квадратов двух других сторон, то этот треугольник прямоугольный .
![1)(\sqrt{15} )^{2}=(2\sqrt{2})^{2}+(\sqrt{7} )^{2}\\\\15=8+7\\\\15=15 1)(\sqrt{15} )^{2}=(2\sqrt{2})^{2}+(\sqrt{7} )^{2}\\\\15=8+7\\\\15=15](https://tex.z-dn.net/?f=1%29%28%5Csqrt%7B15%7D%20%29%5E%7B2%7D%3D%282%5Csqrt%7B2%7D%29%5E%7B2%7D%2B%28%5Csqrt%7B7%7D%20%29%5E%7B2%7D%5C%5C%5C%5C15%3D8%2B7%5C%5C%5C%5C15%3D15)
Треугольник прямоугольный.
![2)(\sqrt{31})^{2} =(\sqrt{17})^{2}+(\sqrt{14})^{2}\\\\31=17+14\\\\31=31 2)(\sqrt{31})^{2} =(\sqrt{17})^{2}+(\sqrt{14})^{2}\\\\31=17+14\\\\31=31](https://tex.z-dn.net/?f=2%29%28%5Csqrt%7B31%7D%29%5E%7B2%7D%20%3D%28%5Csqrt%7B17%7D%29%5E%7B2%7D%2B%28%5Csqrt%7B14%7D%29%5E%7B2%7D%5C%5C%5C%5C31%3D17%2B14%5C%5C%5C%5C31%3D31)
Треугольник прямоугольный
![3)(\sqrt{17})^{2}=(\sqrt{3})^{2}+(\sqrt{14})^{2}\\\\17=3+14\\\\17=17 3)(\sqrt{17})^{2}=(\sqrt{3})^{2}+(\sqrt{14})^{2}\\\\17=3+14\\\\17=17](https://tex.z-dn.net/?f=3%29%28%5Csqrt%7B17%7D%29%5E%7B2%7D%3D%28%5Csqrt%7B3%7D%29%5E%7B2%7D%2B%28%5Csqrt%7B14%7D%29%5E%7B2%7D%5C%5C%5C%5C17%3D3%2B14%5C%5C%5C%5C17%3D17)
Треугольник прямоугольный
![4)(\sqrt{11})^{2}=(\sqrt{7})^{2}+2^{2} \\\\11=7+4\\\\11=11 4)(\sqrt{11})^{2}=(\sqrt{7})^{2}+2^{2} \\\\11=7+4\\\\11=11](https://tex.z-dn.net/?f=4%29%28%5Csqrt%7B11%7D%29%5E%7B2%7D%3D%28%5Csqrt%7B7%7D%29%5E%7B2%7D%2B2%5E%7B2%7D%20%5C%5C%5C%5C11%3D7%2B4%5C%5C%5C%5C11%3D11)
Треугольник прямоугольный
![5)(\sqrt{17})^{2}=(2\sqrt{3})^{2} +(\sqrt{5})^{2}\\\\17=12+5\\\\17=17 5)(\sqrt{17})^{2}=(2\sqrt{3})^{2} +(\sqrt{5})^{2}\\\\17=12+5\\\\17=17](https://tex.z-dn.net/?f=5%29%28%5Csqrt%7B17%7D%29%5E%7B2%7D%3D%282%5Csqrt%7B3%7D%29%5E%7B2%7D%20%2B%28%5Csqrt%7B5%7D%29%5E%7B2%7D%5C%5C%5C%5C17%3D12%2B5%5C%5C%5C%5C17%3D17)
Треугольник прямоугольный
![6)(2\sqrt{3})^{2}=(\sqrt{3})^{2}+(\sqrt{11})^{2}\\\\12=3+11\\\\12=14 6)(2\sqrt{3})^{2}=(\sqrt{3})^{2}+(\sqrt{11})^{2}\\\\12=3+11\\\\12=14](https://tex.z-dn.net/?f=6%29%282%5Csqrt%7B3%7D%29%5E%7B2%7D%3D%28%5Csqrt%7B3%7D%29%5E%7B2%7D%2B%28%5Csqrt%7B11%7D%29%5E%7B2%7D%5C%5C%5C%5C12%3D3%2B11%5C%5C%5C%5C12%3D14)
Неверно, значит треугольник не является прямоугольным.
![7)(3\sqrt{3})^{2}=(\sqrt{10})^{2}+(\sqrt{15})^{2}\\\\27=10+15\\\\27=25 7)(3\sqrt{3})^{2}=(\sqrt{10})^{2}+(\sqrt{15})^{2}\\\\27=10+15\\\\27=25](https://tex.z-dn.net/?f=7%29%283%5Csqrt%7B3%7D%29%5E%7B2%7D%3D%28%5Csqrt%7B10%7D%29%5E%7B2%7D%2B%28%5Csqrt%7B15%7D%29%5E%7B2%7D%5C%5C%5C%5C27%3D10%2B15%5C%5C%5C%5C27%3D25)
Неверно, значит треугольник не является прямоугольным.