plz tell me the answers

16. ABC is a triangle right angled at C. A line through the mid-point M of hypotenuse AB and parallel to BC intersects AC at D. Show that

(i) D is the mid-point of AC (ii) CM = MA = ½ AB17. The dimensions of a room are 9m×8m×6.5m. It has one door of dimensions 2 m×1.5m and two windows each of dimensions 1.5m×1m. Find the cost of white washing the walls at Rs6.40 per sq m.18. In ABC, AD is a median and DE// AB. Prove that BE is a median.19. AB and CD are two parallel lines and a transversal l intersects AB at X and CD at Y. Prove that the bisectors of the interior angles form a rectangle.20. ABC is isosceles with AB= AC. D, E and F are the midpoints of BC, CA and AB. Show that the line segment AD is perpendicular to the line segment EF and is bisected by it.21. In a parallelogram ABCD, E and F are mid-points of sides AB and CD. Prove that the line segments AF and CE trisect the diagonal BD.22. AD and BE are medians of triangle ABC and BE // DF. Point F lies on AC. Prove that CF =  AC.23. Draw the graph of the linear equation whose solutions are represented by the points having the sum of the coordinates as 10 units.24. In parallelogram ABCD, two points P and Q are taken on diagonal BD such that DP =BQ . Show that ΔAPD≅ΔCQB and APCQ is a parallelogram.25. The work done by a body on application of a constant force is the product of the constant force and the distance travelled by the body in the direction of force. Express this in the form of a linear equation in two variables and draw its graph by taking the constant force as 3 units. What is the work done when the distance travelled is 2 units. Verify it by plotting the graph.Hint: Work done = (constant force) × (distance)= 3 × (distance),i.e., y = 3x, where y (units) is the work done and x (units) is the distance travelled.