1. The army faced a formidable enemy in battle.
2. She had a formidable intellect that impressed everyone she met.
3. The towering mountains presented a formidable obstacle to the hikers.
4. The team's defense was formidable, making it difficult for their opponents to score.
5. The storm approaching looked formidable with dark clouds and strong winds.
6. His reputation as a formidable businessman preceded him wherever he went.
7. The professor's knowledge of the subject was truly formidable.
8. The dragon was a formidable creature, breathing fire and causing destruction wherever it went.
9. The concert pianist had a formidable talent that left the audience in awe.
10. The new technology presented a formidable challenge to the company's competitors.