**In a triangle ABC, AD is perpendicular to BC. Prove that AB² + CD² = AC² + BD².**

**Solution:**

**More Solutions:**

- Find the altitude on BC and Hence, calculate its area.
- Find the area and the perimeter.
- Calculate the length of AB.
- Calculate the length of BD.
- Prove that AB2 = 4AD² – 3AC².
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- If diagonals are 30 cm and 40 cm.
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- Prove that 4AD² = 3AB².
- BC and CA respectively of a ΔABC.