1. Find the area (in cm²) of a triangle with base 12 cm and height 7 cm.   Hint Hint       2. 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       3. Calculate the height (in cm to the nearest integer) of an equilateral triangle whose area is 36.95 cm².   Hint       4. 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       5. If the area of an equilateral triangle is 36√3 cm², find its perimeter (in cm).   Hint       6. Find the area (in m²) of an isosceles triangle, each of whose sides is 10 m and base 12 m.   Hint       7. The base of an isosceles triangle is 24 cm and perimeter is 64 cm. Find its area (in cm²).   Hint