ABC is a triangle with AB = AC = 12 cm and ∠A = 90°, the area of the triangle ABC is :

1. 144 cm²

2. 36 cm²

3. 72 cm²

4. 108 cm²

The sides of a triangle are 9 cm, 12 cm and 15 cm; the area of the triangle is :

1. 54 cm²

2. 96 cm²

3. 108 cm²

4. 135 cm²

The lengths of the sides of a triangle are in the ratio 3 : 4 : 5. Find the area of the triangle if its perimeter is 144 cm.

ABC is a triangle in which AB = AC = 4 cm and ∠A = 90°. Calculate :

(i) the area of Δ ABC,

(ii) the length of perpendicular from A to BC.