Area of a Right Angled Triangle

Q. A field is in the shape of a right angled triangle whose base is 25 m and height 20 m. Find the cost of levelling the field at the rate of Rs 45/- per m${}^2$?

Q. Find the corresponding height of a triangle whose base is 4 cm and area is 16 sq cm.

1. 4 sq cm
2. 4 cm
3. 8 sq cm
4. 8 cm