1. 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 Hint       2. Calculate the height (in cm to the nearest integer) of an equilateral triangle whose area is 36.95 cm².   Hint       3. 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       4. The area of a right-angled triangle is 30 times its base. What is its height (in cm)?   Hint       5. If the area of an equilateral triangle is 36√3 cm², find its perimeter (in cm).   Hint       6. The base of a triangle is twice its altitude. If the area of the triangle is 144 cm², find its base (in cm).   Hint       7. Calculate the height (in cm) of a triangle whose base is 24 cm and area is 180 cm².   Hint