Samacheer Kalvi Class 4 Maths Solutions Term 1 Chapter 1 Geometry Exercise 1.5

Tamilnadu Samacheer Kalvi 4th Maths Solutions Term 1 Chapter 1 Geometry Ex 1.5

A. Find the perimeter of the following figures

Question (i) A quadrilateral with sides 6 cm, 8 cm, 3 cm, and 5 cm.
Answer: To find the perimeter, add up the lengths of all the sides of the figure. For this quadrilateral, the sides are 6 cm, 8 cm, 3 cm, and 5 cm long. Adding these lengths (6 + 8 + 3 + 5) gives a total perimeter of 22 cm. The perimeter is the total distance around the shape.
In simple words: You add all the side lengths together: 6 + 8 + 3 + 5. This gives 22 cm.

🎯 Exam Tip: Always make sure to add every side length of a polygon to find its perimeter, even if the sides are different lengths.

Question (ii) A trapezoid with sides 7 cm, 10 cm, 5 cm, and 2 cm.
Answer: To find the perimeter of this figure, we add the lengths of all its sides. The sides are 7 cm, 10 cm, 5 cm, and 2 cm. Adding these lengths together (7 + 10 + 5 + 2) gives a total perimeter of 24 cm. Perimeter is the measure of the boundary of any closed shape.
In simple words: Add all sides: 7 + 10 + 5 + 2. The total is 24 cm.

🎯 Exam Tip: The perimeter is simply the distance around the outer edge of any two-dimensional shape.

Question (iii) A parallelogram with sides 7 cm, 4 cm, 7 cm, and 4 cm.
Answer: For this parallelogram-like figure, the perimeter is found by adding the lengths of all its four sides. The side lengths are 7 cm, 4 cm, 7 cm, and 4 cm. Adding these together (7 + 4 + 7 + 4) results in a perimeter of 22 cm. This shows how opposite sides are equal in parallelograms.
In simple words: Add the sides: 7 + 4 + 7 + 4. The perimeter is 22 cm.

🎯 Exam Tip: Remember that for any polygon, the perimeter is calculated by summing the lengths of all its sides.

Question (iv) A square with each side measuring 11 cm.
Answer: To calculate the perimeter of this square, we add the length of each of its four equal sides. Since each side is 11 cm, the total perimeter is 11 + 11 + 11 + 11, which equals 44 cm. You could also multiply the side length by 4 since all sides are equal.
In simple words: Add all four sides: 11 + 11 + 11 + 11. This gives 44 cm.

🎯 Exam Tip: For a square, a quick way to find the perimeter is to multiply the length of one side by 4.

Question (v) A rectangle with sides 10 cm and 5 cm.
Answer: For this rectangle, we find the perimeter by adding the lengths of all four sides. The two longer sides are 10 cm each, and the two shorter sides are 5 cm each. So, 10 + 5 + 10 + 5 equals 30 cm. Rectangles always have two pairs of equal sides.
In simple words: Add the lengths of all sides: 10 + 5 + 10 + 5. The perimeter is 30 cm.

🎯 Exam Tip: The perimeter of a rectangle can be found by adding the length and width and then multiplying by 2: \( 2 \times (\text{length} + \text{width}) \).

B. Solve the following

Question 1. A side of a square-shaped sandbox in Gandhi Park measures 30 cm. Determine the perimeter of the sand box.
Answer: The sandbox is shaped like a square, and each of its sides measures 30 cm. To find the perimeter, we add all four side lengths together: 30 cm + 30 cm + 30 cm + 30 cm. This sums up to a total perimeter of 120 cm. Since it's a square, you can also multiply the side length by 4.
In simple words: Each side of the square sandbox is 30 cm. Add all four sides (30 + 30 + 30 + 30) to get 120 cm.

🎯 Exam Tip: Remember that all sides of a square are equal, which simplifies perimeter calculations significantly.

Question 2. Find the perimeter of a rectangle, whose sides are 12 cm and 8 cm.
Answer: We need to find the perimeter of a rectangle with sides measuring 12 cm and 8 cm. A rectangle has two pairs of equal sides. So, we add all four sides: 12 cm + 8 cm + 12 cm + 8 cm, which gives a total perimeter of 40 cm. You can also use the formula \( 2 \times (\text{length} + \text{width}) \).
In simple words: The rectangle has sides of 12 cm and 8 cm. Add all four sides (12 + 8 + 12 + 8) to get 40 cm.

🎯 Exam Tip: The perimeter of a rectangle is calculated by adding two times its length and two times its width.

Question 3. Find the perimeter of the triangle, whose sides are 13 cm, 5 cm and 14 cm.
Answer: To find the perimeter of a triangle, we simply add the lengths of all its three sides. For this triangle, the sides are 13 cm, 5 cm, and 14 cm. When we add these lengths together (13 + 5 + 14), the total perimeter is 32 cm. The perimeter represents the total boundary length of the triangle.
In simple words: Add all three side lengths of the triangle: 13 + 5 + 14. The total perimeter is 32 cm.

🎯 Exam Tip: For any triangle, its perimeter is always the sum of its three side lengths, regardless of its shape.

Question 4. The adjacent sides of a parallelogram are 6 cm and 7 cm. What is the perimeter of the parallelogram?
Answer: A parallelogram has opposite sides that are equal in length. If two adjacent sides are 6 cm and 7 cm, then the other two sides will also be 6 cm and 7 cm respectively. So, the perimeter is 6 cm + 7 cm + 6 cm + 7 cm, which equals 26 cm. You can also use the formula \( 2 \times (\text{side 1} + \text{side 2}) \).
In simple words: A parallelogram has opposite sides equal. So, the sides are 6 cm, 7 cm, 6 cm, and 7 cm. Add them all (6 + 7 + 6 + 7) to get 26 cm.

🎯 Exam Tip: Remember that opposite sides of a parallelogram are equal, which is key to finding its perimeter.

Question 5. The sides of a trapezoid measures 8 cm, 7 cm, 4 cm and 5 cm respectively. What is the perimeter of the trapezoid?
Answer: To find the perimeter of a trapezoid, we add the lengths of all its four sides. The given side lengths are 8 cm, 7 cm, 4 cm, and 5 cm. Adding these together (8 + 7 + 4 + 5) gives a total perimeter of 24 cm. The perimeter shows the total length around the outer boundary of the trapezoid.
In simple words: Add all four sides of the trapezoid: 8 + 7 + 4 + 5. The total perimeter is 24 cm.

🎯 Exam Tip: For any four-sided figure (quadrilateral) with unequal sides, simply add all four distinct side lengths to find the perimeter.