Mathematics
A wire when bent in the form of a square encloses an area = 576 cm2. Find the largest area enclosed by the same wire when bent to form:
(i) an equilateral triangle.
(ii) a rectangle whose adjacent sides differ by 4 cm.
Mensuration
8 Likes
Answer
(i) Area of the square = 576 cm2
Let a be the length of side of the square.
⇒ a2 = 576
⇒ a =
⇒ a = 24 cm
Total length of the wire = Perimeter of the square = 4 x 24 cm = 96 cm
Perimeter of the square = Perimeter of equilateral triangle.
⇒ 3 x side = 96 cm
⇒ side = cm
⇒ side = 32 cm
Area of equilateral triangle = x side2
= x (32)2 cm2
= x 1,024 cm2
= 256 cm2
Hence, the area of equilateral triangle is 256 cm2.
(ii) Given:
Let l be the length and b be the breadth of the rectangle.
l - b = 4 ……………(1)
Perimeter of rectangle = Perimeter of square
⇒ 2(l + b) = 96 cm
⇒ 2(l + b) = 96 cm
⇒ l + b = cm
⇒ l + b = 48 cm ……………(2)
Add equation (1) and (2), we get
⇒ (l - b) + (l + b) = 4 + 48
⇒ l - b + l + b = 52
⇒ 2l = 52
⇒ l =
⇒ l = 26 cm
So, b = l - 4 = 26 - 4 = 22 cm
Area of rectangle = l x b
= 26 x 22 cm2
= 572 cm2
Hence, the area of rectangle is 572 cm2.
Answered By
3 Likes
Related Questions
ABCD is a square with each side 12 cm. P is a point on BC such that area of Δ ABP : area of trapezium APCD = 1 : 5. Find the length of CP.
A rectangular plot of land measures 45 m x 30 m. A boundary wall of height 2.4 m is built all around the plot at a distance of 1 m from the plot. Find the area of the inner surface of the boundary wall.
The area of a parallelogram is y cm2 and its height is h cm. The base of another parallelogram is x cm more than the base of the first parallelogram and its area is twice the area of the first. Find, in terms of y, h and x, the expression for the height of the second parallelogram.
The distance between parallel sides of a trapezium is 15 cm and the length of the line segment joining the mid-points of its non-parallel sides is 26 cm. Find the area of the trapezium.