2.1 INTRODUCCIÓN:
-Clasificación de los triángulos según sus lados:
1º T.equilátero:Sus lados son iguales(A=B=C)
![Resultado de imagen de triangulo equilatero](data:image/jpeg;base64,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)
2º T isósceles: dos lados iguales y uno desigual.(A=B/C)
![Resultado de imagen de triangulos isosceles](data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxASERUOEBITFRUVFhkVGBYWGBUXHhUfFxYaIhYXGRgZHyghGhsmHx8VJTIiJSktLi8uHigzODMsNyo1Li0BCgoKDg0OGRAQGjciICUtLTg3Ly8tLi0rLS0tNystLy0tLS0vLy0tLS4vKy0tLS0tLS8rLS0tLS0tLS0tLS0tK//AABEIAJkAYwMBIgACEQEDEQH/xAAbAAEAAgMBAQAAAAAAAAAAAAAABQYBAwQCB//EADsQAAICAQEEBQsDAgYDAAAAAAECAAMRBAUSITEGEyJRgRUyQUJhcXKRkpPRFFNUYoJSoaKx4fEHIyT/xAAYAQEBAQEBAAAAAAAAAAAAAAAAAgMBBP/EAB4RAQEAAwEBAQADAAAAAAAAAAABAhESAyExQXGh/9oADAMBAAIRAxEAPwD7jERAREQE16i5URrGOFUFie4AZJmyVvp3qD+mGmXztTYtI9zHLnwUGTllzLSTbp6Ibd/W6YXlQjbzKyAk7pHEcT3qVPjJuU/YONPr3oHBNRUHUf1Vdlh9JT/KW+T55dY7ds1dMxETRwiIgIiICIiAiIgJStq6hbtpqhYbumqOOPN7efyUCXG+1UVrGOFUFie4AZJlO2YEXSHV31B31FnW7rAc7WArXJ5YG4M+yYe+7jqL87JlNtfSS3qhVqwRvae1XxkZKns2Af2ky7owIDA5B4g++VnR6Siw3ad9PUjLhG3e0CLF4EMVBBxn0Tr6G6hm0orc5ehmof318AfFd0+Mnw3P3+XfW49fE7ERPSzIiICIiAiIgIiIFf6Z2E0rpVPa1Ni0+5TxsPgoaaek+E064BwttOAOJwLVwAPSYtPXbRJ9XS1bv993E/JVHzknq9KlihHGQGVuZHFSCvL2gTDOdbdxsmW6i9j1YvuapXWllQ9tXXes47zKHAbG7uAnlkT1oD1O0LK/V1VYtHx1dl/mpQyYkJ0pyiV6wc9Path+A9m0fST8ok5jmWW7taImFYEZByDxB75mbhERAREQEREBNd9yorOxwqgsT3ADJM2Sv9M7CaF0qntamxaeHoU8bD4KGnLdQaOidbGg6hxh9Q7XsD6N/wAweChRJqeUQABQMAAADuA5CeplEk1amhbEaphlXUqR7GGDNsQODodqWbSrW5y9DNQ/vr4A+K7p8ZOStaA9TtCyv1dTWLR8dXZf5qUMssvC/FEREsIiICaNXqNwZCO5JwFUZJ8TgD3kib5GbcovdU6liAHzYobcLrg8A44qc7p4d2Jyqwkt1W/ZuvS5SygjdYoysMFWU8Qf+OEhrT120SfV0tW6Pju4t8lVfdn2zq2FpG01VzXkAGx7c7zPhcDmzcSRgzk6K1saP1DjD6h2vbPo3/MHgoUeEjK/JK76zGZWY/iZiIksiIiBCdKQUSvWLz01q2HHpQ9m0fSTLIbBu7/MYzwBORj0AcT4Ti1FKujVsMq6lSO8MMGR3R2219C1Kvu307+n3iM4ZBhGI9242PbO43Vqsf1I6XaivaaGSyt93fAcDtLnGQQT6fQcEZHCSIla2RsvULqEvtzwqKNvWtYSxKkkZGAvA8Bj3SyiXjvX1r64442c0iIlMiYMzECA6YuTSulU4bU2LT7lPGw+CBpIqoAAAwBwA7gOUiHbrtosfV0tW6Pju4t8lVfn7ZMTK3dcIiJxwiIgJEaE9TtB6/V1NYsHx1dl/mpQ+HskvITpRlEr1i89NYth+A9m0fSTH59FnmZ5RgQCOIPEGepsoiIgJr1FyojWMcKoLE9wAyTNkr/TSwtSukU4bU2LVw9C87D4KDOW6g09FK26jr3GH1DNe3s3/NHgu6PCTMwqgAADAAwB3AchMzKJIiICIiAmrU0LYjVsMq6lSO8MMGbYgcHQ3Us2mFTnL0M1D++vzT4runxk5K1oT1O0HTkmqrFg+Org/wA1KGWWXhfiiIiWMStOeu2izerpago+O7i3iFVfnLFfcqK1jHCqCxPcAMkyg7A09j1nWb7V3Xu1pOcjDHsIy8iAuB3+2c56umXrnzPza6MQBk8AO+eK7kbG6ynPEYIOcc8Ylf2pa+p0xQIS9dtfXVDjvorguq585WXOB6eU87H0/wD999/U2Ij1otRKFVOCeuOMf+skivg2M4nONb27M5lJYs0REzUREQPFtqr5zKueAyQM+zjMqwPIg+jhx8JA7VoP6rrbKWuqOnNaqqb+65clgR6u+u6N48OHEiOiFX6fRKtwdGr3jb1gPnZJY7x88f1DOZfPzbly029KgUSvWLz01q2H4Cd20fSTLMjAgEcQRkeMqGpD6oHrSyVMCBUDgsD6bCOPH/Dy78yQ6Dapn0oqc5ehmob+zzT4qVPjK44ukefr3fiwxMRDZV//ACDrgmmGn3wp1DirJOMLzsbwX/cd85E2tpFAVbqgAMAbw4Achzlt1WiqtwLa0fHEb6q2PdnlOfyLpf49H20/ETcu2efn1VX0+2NMupRxfVh0ZH7Q9XBQn/UPGTXlzSfyKfrX8zvGxtL6NPT9tPxM+SdN+xT9tPxOZ9ZOefnxKj/Lmk/kU/Wv5jy5pP5FP1r+ZIeSdN+xT9tPxHknTfsU/bT8Sea00j/Lmk/kU/Wv5jy5pP5FP1r+ZwWajTV6u6iyircSqt1CUb7dovvk7oPDgvok3p9n6R1FiU0MrAEEImCDyI4SZLfxpn5ZYatn64/Lmk/kU/Wv5kXt3bOmYV1C+oqzgvhxyUE4PsJAlk8k6b9in7afiYOx9Keenp+2n4mmMuN2wzw6x0rXlnS/v1fUs1dG9pVLtCyquxGXUVh+yQcPXkMPFcH/AKlp8i6X+PR9tPxNlGy9OjB0pqVhyZUUEZ54IE7d1zHz5u9uqJmIakRE6EREBMTJmDAr1+n1Feru1FdPWLZVWi4dFO8u/wA94js8Rk8+4GSWwdCaNNVp2IJrQKSOWRzx7J3wZMxka5e2WWPP9f58jMREpkREQERED//Z)
3º T escaleno:No tiene ningún lado igual(A/B/C)
![Resultado de imagen de triangulo escaleno](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ6zQAPbVK945Y97zouxJhowfFhq2RlOJ-NRDrhegYOL5ch-3uWhA)
Nota:Este triangulo también es rectángulo(90º)
3º T escaleno:No tiene ningún lado igual(A/B/C)
Nota:Este triangulo también es rectángulo(90º)