2. From a point in the interior of an equilateral triangle, perpendiculars drawn to the three sides are 8 cm, 10 cm and 11 cm respectively. Find the area of the triangle. [486.1 cm2]

3. The difference between the sides at right angles in a right-angled triangle is 14 cm. The area of the triangle is 120 cm2. Calculate the perimeter of the triangle. [24 cm, 10 cm, 60 cm.]

4. Find the percentage increase in the area of a triangle if its each side is doubled? [300%]

5. Calculate the area of the triangle whose sides are 18 cm, 24 cm and 30 cm in length. Also, find the length of the altitude corresponding to the smallest side of the triangle.

6. The sides of a triangle are 10 cm, 24 cm and 26 cm. Find its area and the longest altitude.

7. Two sides of a triangular field are 85 m and 154 m in length, and its perimeter is 324 cm. Find (i) the area of the field, and (ii) the length of the perpendicular from the opposite vertex on the side measuring 154 cm.

8. The sides of a triangular field are 165 cm, 143 cm and 154 cm. Find the cost of ploughing it at 12 paise per sq. m.

9. The base of an isosceles triangle measures 80 cm and its area is 360 cm2. Find the perimeter of the triangle.

10. The perimeter of an isosceles triangle is 42 cm and its base is 11/2 times each of the equal sides. Find (i) the length of each side of the triangle, (ii) the area of the triangle, and (iii) the height of the triangle.

11. The perimeter of a right angle triangle is 40 cm. Its hypotenuse is 17 cm. Find the sides containing the right angle. Also find the area of the triangle.