1. The base of a triangular field is five times its height. If the cost of cultivating the field at $32 per hectare is $500, find its height (in m). Note that 1 hectare = 10000 m2.   Hint Hint       2. Calculate the side (in cm to the nearest integer) of an equilateral triangle whose height is 10.4 cm.   Hint       3. Calculate the area (in cm² upto 1 decimal place) of an equilateral triangle of side 10 cm.   Hint       4. The base of a right-angled triangle is 5 cm and its hypotenuse is 13 cm. Find the area (in cm²) of the triangle.   Hint       5. The lengths of the sides of a triangle are in the ratio 3 : 4 : 5 and its perimeter is 72 cm. Find the area (in cm²) of the triangle.   Hint       6. If the area of an equilateral triangle is 36√3 cm², find its perimeter (in cm).   Hint       7. Find the area (in cm²) of a triangle with base 12 cm and height 7 cm.   Hint