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Perimeter = ? Length = 2x Breadth = x |
| Answer» ANGLE, the distance around the outside of the rectangle is known as perimeter. A rectangle is 2-dimensional; however, perimeter is 1-dimensional and is measured in linear units such as feet or meter etc.The perimeter of a rectangle is the TOTAL length of all the four sides.Perimeter of rectangle = 2L + 2W.Example 1: Rectangle has the length 13 cm and width 8 cm. solve for perimeter of rectangle.Solution:Given that:Length (l) = 13 cmWidth (w) = 8 cmPerimeter of the rectangle = 2(l + w) unitsP = 2(13 + 8)P = 2 (21)P = 42Thus, the perimeter of the rectangle is 42 cm.Example 2: If a rectangle's length is 2x + 1 and its width is 2x – 1. If its area is 15 cm2, what are the rectangle's dimensions and what is its perimeter?Solution:We know that the dimensions of the rectangle in terms of x: l = 2x + 1w = 2x – 1Since the area of a rectangle is given by:A = l * wWe can substitute the expressions for length and width into the equation for area in order to determine the value of x.A = l * w15 = (2x + 1) (2x -1)15 = 4x2 – 116 = 4x2x = ±2 Note that the value of x must be positive and therefore in our case, the value of x is 2. And now we have:l = 5 cmw = 3 cmTherefore, the dimensions are 5cm and 3cm.Now, substituting these values in the formula for perimeter, we will getP = 2l + 2wP = 2(5)+2(3)P = 10+6P = 16 cmExample 3: Find the area and the perimeter of a rectangle WHOSE length is 24 m and width is 12m?Solution:Given that:length = L = 24mwidth = W = 12mArea of a rectangle:A = L × WA = 24 × 12A = 188 m2Perimeter of a rectangle:P = 2L + 2WP = 2(24) + 2(12)P = 48 + 24P = 72 mExample 4: Find the area and perimeter of a rectangle whose breadth is 4 cm and the height 3 cm.Solution:Area = b×h = 4×3 = 12 cm2.Perimeter = 2(b) + 2(h) = 2(4) + 2(3) = 8 + 6 = 14.Example 5: Calculate the perimeter of the rectangle whose length is 18cm and breadth 7cmSolution:Given that:L = 18 cmB = 7 cmPerimeter of rectangle = 2(length + breadth)P = 2 (L + B)P = 2 (18 + 7)P = 50 cmExample 6: Find the perimeter of rectangle whose length is 6 inches and width is 4 inches.Solution:P = 2(L + B)P = 2(6 + 4)P = 20 inExample 7: A boy walks 5 times around a PARK. If the size of the park is 100m by 50m, find the distance the boy has walked. If he walks 100m in 5 minutes, how long will it take for him in total?Solution:Given that:Length = L = 100mWidth = W = 50mRounds = 5Time per 100m = 5minutes.Perimeter of the park:P = 2 L + 2 W.P = 2 × 100 + 2 × 50P = 200 + 100P = 300 mTotal distance walked = 5 × Perimeter of the park.= 5 × 300= 1500 metersTotal time taken = Total distance walked × time taken to walk 1m.= 1500 × 5/100= 75minutes or 1hr 15minutes | |