Geometry help please……

1. Find the area of the triangle whose sides are 13cm, 14cm and 15cm. 
2. Prove that the length of the altitude of an equilateral triangle of side ‘a’ is √3/2a

3. The sides of a triangular field are 120m, 160m & 200m. Find the cost of ploughing it at the cost of 25 paise per square m.

4. The length of sides of a right angled triangle forming the right angle are 5x cm and (3x – 1) cm. If the area of the triangle is 60 cm2, find its all sides

5. Find the perimeter of an isosceles right angled triangle having area 200 cm2.

6. Find the area of a quadrilateral ABCD in which AB = 3cm, BC = 4 cm, CD = 4 cm, DA = 5 cm and AC = 5cm. 

7. A triangle and a parallelogram have the same base and the same area. If the sides of the triangle are 26cm, 28cm and 30cm, and parallelogram stands on the base 28cm, find the height of the parallelogram. 

8. A field is in the shape of trapezium whose parallel sides are 25m and 10m. The non-parallel sides are 14m and 13m. Find its area. 

9. A rectangular has twice the area of square. The length of rectangle is 12 cm longer and the width is 8cm longer than the sides of the square. Find the area of the square.

10. The diagonals of a rhombus are whose 15 and 36 cm long. Find its perimeter.