(1) 20(ii) 21 cm, 20 cm, 13 cmThe area of a triangle is 6 cm- and its base is 4 cm. Find its height.5. In the adjoining figure, ABCD represents asquare of side 6 cm. E is a point on DC suchthat the area or the triangle ADE is one-thirdof the area of the square. Find the lengthof ED.0 ECtio 25:17:12. Find the area6. The perimeter of a triangle is 540 m and its sides are in the ratio 25:17:12. Findof the triangle.7. In a A ABC, AB = AC = 4 cm and ZA = 90°. Calculate the area of A ABC.8. Find the area of the equilateral triangle whose each side is : (i) 12 cm G m9. Find the area of a triangle with base 5 cm and whose height is equal to that of awith base 5 cm and area 20 cm.10 The sides of a triangular field are 973 m, 100 m and 1125 m. If this field is sold at theof 1000 per hectare, find its selling price.11. The base of an isosceles triangle is 24 cm and its area is 192 sq. cm. Find its per12. The area of an equilateral triangle is 173.2 m-. Find its perimeter.13. Find the area of the isosceles triangle whose :(1) each of equal sides is 8 cm and the base is 9 cm.(ü) each of the equal sides is 10 cm and the base is 12 cm.(ii) each of the equal sides is 7.4 cm and the base is 6.2 cm.(iv) perimeter is 11 cm and base is 4 cm.i d ne nf a triangle are 42 cm, 34 cm and 20 cm. Calculate its area a​