In a triangleSum of two sides is always greater than 3rd side i.e., x < 25 + 15 = 40 .....(i)Difference of two sides is always less than 3rd side i.e., 25 - 15 = 10 < x ...(ii) From Eqs. (i) and (ii) , we get 10 < x < 40
Let length of the longer diagonal = d cmThen, length of other diagonal = 0.8 x d cm Area of rhombus = (1/2) x d x 0.8 x d = 2/5 d2= 2/5 d2Area of square of the length of the longer diagonal = d2So the area of the rhombus is 2/5 times the square of the length of the longer diagonal.
Let l = 4k and b = 9kArea of rectangle = l x b144 = 4k x 9k ? k2 = 144/36 ? k2 = 4? k = 2? l = 8 cm and b = 18 cmPerimeter of rectangle = 2(l + b)= 2(8 + 18)= 2 x 26= 52 cm