The three sides of a triangular field are 20 metres, 21 metres and 29 metres long respectively. The area of the field is :

Answer: Option A

Since (20)² + (21)² = (29)²
So, it is a right-angled triangle with base = 20 m and height = 21 m
∴ Area = $$\left(\frac{1}{2}\times 20\times 21\right)$$   m² = 210 m²