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About Perimeter and Area — Class 7 Olympiad

Calculate perimeter and area of triangles, quadrilaterals, and circles; solve composite figure challenges. This topic is part of the Olympiad Class 7 mathematics syllabus (chapter: Module 10). On this page you can practice 58 questions across three difficulty levels — 18 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 35-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Perimeter and Area — solved examples for Class 7 Olympiad

Example 1easy

A wire of length 48 cm is bent to form a square. If the same wire is re-bent to form a rectangle of length 14 cm, what will be the difference in the areas of the square and the rectangle?
  1. A)4 cm²
  2. B)9 cm²
  3. C)16 cm²
  4. D)25 cm²

Step-by-step solution

  1. For the square: Perimeter = 48 cm. Side of square = 48 cm / 4 = 12 cm. Area of square = side × side = 12 cm × 12 cm = 144 cm².
  2. For the rectangle: Perimeter = 48 cm. Length = 14 cm. Perimeter = 2 × (Length + Breadth). So, 48 = 2 × (14 + Breadth). 24 = 14 + Breadth. Breadth = 24 - 14 = 10 cm.
  3. Area of rectangle = Length × Breadth = 14 cm × 10 cm = 140 cm².
  4. Difference in areas = Area of square - Area of rectangle = 144 cm² - 140 cm² = 4 cm².

Answer: 9 cm²

Example 2medium

A rectangle ABCD has length AB = 12 cm and width BC = 8 cm. Point P is the midpoint of side AB, and point Q is the midpoint of side BC. What is the area of triangle DPQ?
  1. A)32 cm²
  2. B)36 cm²
  3. C)40 cm²
  4. D)48 cm²

Step-by-step solution

  1. The total area of the rectangle ABCD is length × width = 12 cm × 8 cm = 96 cm².
  2. P is the midpoint of AB, so AP = PB = 12/2 = 6 cm. Q is the midpoint of BC, so BQ = QC = 8/2 = 4 cm.
  3. Area of triangle ADP = (1/2) × base AP × height AD = (1/2) × 6 cm × 8 cm = 24 cm².
  4. Area of triangle BPQ = (1/2) × base PB × height BQ = (1/2) × 6 cm × 4 cm = 12 cm².
  5. Area of triangle CDQ = (1/2) × base CD × height CQ = (1/2) × 12 cm × 4 cm = 24 cm².
  6. The area of triangle DPQ is the area of the rectangle minus the sum of the areas of the three surrounding triangles: 96 cm² - (24 cm² + 12 cm² + 24 cm²) = 96 cm² - 60 cm² = 36 cm².

Answer: 36 cm²

Example 3hard

How many distinct rectangles exist such that their side lengths are positive integers and their area is numerically equal to their perimeter?
  1. A)(A) 1
  2. B)(B) 2
  3. C)(C) 3
  4. D)(D) 4

Step-by-step solution

  1. Let the length be L and width be W. The given condition is LW = 2(L+W).
  2. Rearrange the equation: LW - 2L - 2W = 0. Add 4 to both sides: LW - 2L - 2W + 4 = 4.
  3. Factor by grouping: L(W-2) - 2(W-2) = 4, which simplifies to (L-2)(W-2) = 4.
  4. Since L and W are positive integers, (L-2) and (W-2) must be integer factors of 4. Possible pairs for (L-2, W-2) are (1,4), (4,1), and (2,2). These yield (L,W) pairs as (3,6), (6,3), and (4,4). Considering distinct rectangles (3x6 is the same as 6x3), there are 2 distinct rectangles: 3x6 and 4x4.

Answer: (B) 2

Practice questions on Perimeter and Area

  1. Q1.easy

    A rectangular sheet of paper has a length of 20 cm and a width of 15 cm. A triangular piece is cut from one corner such that its base is 8 cm and its height is 6 cm (along the sides of the rectangle). What is the area of the remaining paper?
    1. A)252 cm²
    2. B)260 cm²
    3. C)276 cm²
    4. D)282 cm²
    Show answer

    Answer: 276 cm²

    Hint: First, calculate the total area of the rectangular sheet. Then, find the area of the triangular piece that was removed.

  2. Q2.easy

    A bicycle wheel has a diameter of 70 cm. How many revolutions will it make to cover a distance of 1.1 km? (Take π = 22/7)
    1. A)500
    2. B)550
    3. C)600
    4. D)1000
    Show answer

    Answer: 500

    Hint: One revolution covers a distance equal to the circumference of the wheel. Remember to convert all units to be consistent.

  3. Q3.easy

    The area of a triangular field is 1200 m². If its base is 60 m, what is the height corresponding to this base?
    1. A)20 m
    2. B)30 m
    3. C)35 m
    4. D)40 m
    Show answer

    Answer: 40 m

    Hint: Recall the formula for the area of a triangle. You'll need to work backward to find the height.

  4. Q4.medium

    A square of side 10 cm has a smaller square of side 2 cm cut out from one of its corners, as shown in the figure (imagine a corner removed). What is the perimeter of the remaining shape?
    1. A)40 cm
    2. B)36 cm
    3. C)44 cm
    4. D)48 cm
    Show answer

    Answer: 40 cm

    Hint: Carefully trace the new boundary. Notice how cutting a square from a corner affects the lengths of the sides.

  5. Q5.medium

    A rhombus has diagonals in the ratio 3:4. If its area is 96 cm², what is the sum of the lengths of its diagonals?
    1. A)24 cm
    2. B)28 cm
    3. C)32 cm
    4. D)36 cm
    Show answer

    Answer: 28 cm

    Hint: Recall the formula for the area of a rhombus in terms of its diagonals. Let the diagonals be 3x and 4x.

  6. Q6.medium

    A circular wheel of radius 14 cm makes 250 revolutions to cover a certain distance. What is the distance covered in kilometers? (Use π = 22/7)
    1. A)0.11 km
    2. B)0.18 km
    3. C)0.22 km
    4. D)0.25 km
    Show answer

    Answer: 0.22 km

    Hint: First, calculate the circumference of the wheel. The total distance is the circumference multiplied by the number of revolutions, then convert units.

  7. Q7.hard

    In triangle ABC, D is a point on BC such that BD:DC = 1:2. E is a point on AC such that AE:EC = 1:3. If the area of triangle ABC is 72 cm², what is the area of triangle BDE?
    1. A)(A) 12 cm²
    2. B)(B) 16 cm²
    3. C)(C) 18 cm²
    4. D)(D) 24 cm²
    Show answer

    Answer: (C) 18 cm²

    Hint: Use the property that if two triangles share the same height, the ratio of their areas is equal to the ratio of their bases.

  8. Q8.hard

    A parallelogram has a perimeter of 80 cm. The ratio of the lengths of its adjacent sides is 3:5. If the altitude corresponding to the longer side is 12 cm, what is the area of the parallelogram?
    1. A)(A) 180 cm²
    2. B)(B) 240 cm²
    3. C)(C) 300 cm²
    4. D)(D) 360 cm²
    Show answer

    Answer: (C) 300 cm²

    Hint: Use the perimeter and side ratio to find the actual lengths of the sides first. Then apply the area formula for a parallelogram.

  9. Q9.hard

    A circular wire of radius 'r' is bent to form a square. What is the ratio of the area of the square to the area of the original circle?
    1. A)(A) 4/π
    2. B)(B) π/4
    3. C)(C) 4/(π²)
    4. D)(D) π/(4π)
    Show answer

    Answer: (B) π/4

    Hint: The length of the wire remains constant. Equate the circumference of the circle to the perimeter of the square.

These are 9 of the 58 questions available for Perimeter and Area. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.