Trine and trikona house in astrology:
Planets placed in those houses are strong and have a capacity to express their energy fully. Benefic planets placed here are very supportive and add to the longevity and success in life, while malefic can cause a great deal of difficulties (if badly placed).
The 8th house shows hidden devotion, it relates from previous bad deeds or bad karmas and awakening of the Kundalini, this houses shows people have mastery over the mind and can go the particular way which will be different from others and always search of origin and hidden facts of life.
You can observe one important point about 8th house, very strongly placed planet in 8th house will not give harm to you but it will not give money in your salary, it can give inherited money but always in later age.
The 12th house shows new world after this materialistic world, it confers new definition of spiritualism and moksha. Moksha obtain possible in this birth or not. It is the path of Spiritualism, Cosmic energy, renunciation and surrender.