Bài 6.
a)
`\hat{ABD}<\hat{ACB}<\hat{BAC}<\hat{DBC}<\hat{ABC}`
(20° < 30° < 40° < 90° < 110°)
b)
`\hat{ADB}` = 120° => Góc tù
`\hat{BDC}` = 60° => Góc nhọn
`\hat{ADC}` = `80° => Góc bẹt
Bài 7.
`\hat{ABC}` = 60°
`\hat{ACB}` = 30°
`\hat{BAC}` = 90°
Bài 8.
`\hat{ABC}` = 46°
`\hat{ACB}` = 44°
`\hat{BAC}` = 90°
`\hat{BDC}` = 28°
`\hat{BCD}` = 49°