What does this troparion say?

That the Nativity of the Most Holy Theotokos made people happy; because Jesus Christ was born of Her, Who abolished curse and death and gave us eternal blessed life.

Why is Jesus Christ called the Sun of Righteousness?

Because He, like the sun that illuminates the earth, enlightens every person with the light of true faith.

Troparion of the Exaltation of the Cross of the Lord (Feast of September 14)

Troparion of the Entry of the Most Holy Theotokos into the Temple (Feast of November 21)

In Russian:

Now is the day of God's goodwill (to us) and the herald of the salvation of people: the Virgin solemnly appears in the temple of God and foretells everyone about Christ. To Her we cry out at the top of our voices: Rejoice, fulfillment of the Creator's providence for us.

Prefiguration is an omen. Loudly - loudly, solemnly. Looking is providence. The creator is the creator.

In this troparion it is said that the appearance of the Virgin Mary in the temple (chosen to be the Mother of our Lord and Savior) foretells salvation to people.

Troparion of the Nativity of Christ (Feast of December 25)

In Russian:

Thy birth, Christ our God, illumined the world with the light of the knowledge of God, for at that time those who served the stars as God were taught by the star to worship Thee, the Sun of righteousness, and to know Thee, O East, from on high. Lord, glory to You.

Vedeti - to know.

This troparion says that the birth of the Saviour was a spiritual light for people, because by the miraculous star that appeared at the birth of the Saviour, the Eastern sages came to know Him.

Who are the servants of the stars?

The Eastern sages, who divined the fate of man by the currents of the stars, and who, by the appearance of a special star in the sky, learned of the birth of the Saviour.

Who is this East from above?

This is our Savior Jesus Christ, who enlightens us with faith from the heavenly heights, just as the rising sun in the east pours daylight over the earth and revives it.