The base of a right-angled triangle is 8 cm and its hypotenuse is 10 cm. The area of the triangle is:

1. 80 cm²

2. 40 cm²

3. 48 cm²

4. 24 cm²

The area of a triangle with sides 4 cm, 3 cm and 5 cm is:

1. 12 cm²

2. 15 cm²

3. 10 cm²

4. 6 cm²

The altitude of an isosceles triangle is 4 cm and its base is 2 cm more than its height. The area of the triangle is :

1. 24 cm²

2. 12 cm²

3. 16 cm²

4. 8 cm²