Помогите решить пожалуйста очень нужно !!!
1.a² = b² + c² - 2bc cos120° = 100 + 144 - 2* 10*12 *(-1/2) = 364; a = 18; 5. p = (4+13+15)/2 = 16; } = \sqrt{x=16(16-4)(16-13)(16-15)} = \sqrt{576} =24; R =
![S_{[tex] \frac{abc}{4S} = \frac{4*13*15}{4*24} = \frac{65}{8}; r = \frac{S}{p} = \frac{24}{16} = 3/2](https://tex.z-dn.net/?f=+S_%7B%5Btex%5D+%5Cfrac%7Babc%7D%7B4S%7D+%3D++%5Cfrac%7B4%2A13%2A15%7D%7B4%2A24%7D+%3D+%5Cfrac%7B65%7D%7B8%7D%3B++r+%3D+%5Cfrac%7BS%7D%7Bp%7D+%3D++%5Cfrac%7B24%7D%7B16%7D+%3D+3%2F2++++ "S_{[tex] \frac{abc}{4S} = \frac{4*13*15}{4*24} = \frac{65}{8}; r = \frac{S}{p} = \frac{24}{16} = 3/2")
} = \sqrt{x=16(16-4)(16-13)(16-15)} = \sqrt{576} =24; R =