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Free Grade 3 Introducing Area Under a Curve Lessons

Free Grade 3 lessons for Introducing Area Under a Curve: 12 real questions with a full answer key and worked solutions. Perimeter is the distance around a shape; area is the space inside. Rectangle area = length × width; triangle = ½ × base × height; circle = πr².

Price

Free

Difficulty

Higher

Estimated time

35 min

Total marks

24

Learning objectives

Every objective is checkable, and each one maps to an activity and an assessment.

  • RememberIdentify introducing area under a curve

    Identify introducing area under a curve accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • UnderstandExplain introducing area under a curve

    Explain introducing area under a curve accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • ApplyCalculate introducing area under a curve

    Calculate introducing area under a curve accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • AnalyseCompare introducing area under a curve

    Compare introducing area under a curve accurately in a familiar context.

    Assessed by: Exit ticket of four short items

Prerequisites

Close these gaps first — each has its own free lesson, worksheet and quiz.

How Introducing Area Under a Curve works

Perimeter is the distance around a shape; area is the space inside. Rectangle area = length × width; triangle = ½ × base × height; circle = πr².

Key wordsperimeterareasquare unitsradiuscircumference

12 practice questions

Easy to hard, 24 marks in total. Try them first, then open the answers.

  1. 1.A rectangle is 5 cm by 10 cm. Find its perimeter and area.[1]
  2. 2.A rectangle is 6 cm by 13 cm. Find its perimeter and area.[1]
  3. 3.A rectangle is 10 cm by 9 cm. Find its perimeter and area.[1]
  4. 4.A rectangle is 15 cm by 13 cm. Find its perimeter and area.[1]
  5. 5.A triangle has base 6 cm and height 12 cm. Find its area.[2]
  6. 6.A triangle has base 8 cm and height 5 cm. Find its area.[2]
  7. 7.A triangle has base 30 cm and height 2 cm. Find its area.[2]
  8. 8.A triangle has base 8 cm and height 14 cm. Find its area.[2]
  9. 9.Find the area and circumference of a circle with radius 5 cm (to 1 d.p.).[3]
  10. 10.Find the area and circumference of a circle with radius 9 cm (to 1 d.p.).[3]
  11. 11.Find the area and circumference of a circle with radius 2 cm (to 1 d.p.).[3]
  12. 12.Find the area and circumference of a circle with radius 8 cm (to 1 d.p.).[3]
Show answers and working
  1. 1. Perimeter 30 cm, area 50 cm²

    Perimeter = 5 + 10 + 5 + 10 = 30 cm. Area = 5 × 10 = 50 cm².

  2. 2. Perimeter 38 cm, area 78 cm²

    Perimeter = 6 + 13 + 6 + 13 = 38 cm. Area = 6 × 13 = 78 cm².

  3. 3. Perimeter 38 cm, area 90 cm²

    Perimeter = 10 + 9 + 10 + 9 = 38 cm. Area = 10 × 9 = 90 cm².

  4. 4. Perimeter 56 cm, area 195 cm²

    Perimeter = 15 + 13 + 15 + 13 = 56 cm. Area = 15 × 13 = 195 cm².

  5. 5. 36 cm²

    Area = ½ × base × height. ½ × 6 × 12 = 36 cm².

  6. 6. 20 cm²

    Area = ½ × base × height. ½ × 8 × 5 = 20 cm².

  7. 7. 30 cm²

    Area = ½ × base × height. ½ × 30 × 2 = 30 cm².

  8. 8. 56 cm²

    Area = ½ × base × height. ½ × 8 × 14 = 56 cm².

  9. 9. Area 78.5 cm², circumference 31.4 cm

    Area = πr² = π × 5² = 78.5 cm². Circumference = 2πr = 2 × π × 5 = 31.4 cm.

  10. 10. Area 254.5 cm², circumference 56.5 cm

    Area = πr² = π × 9² = 254.5 cm². Circumference = 2πr = 2 × π × 9 = 56.5 cm.

  11. 11. Area 12.6 cm², circumference 12.6 cm

    Area = πr² = π × 2² = 12.6 cm². Circumference = 2πr = 2 × π × 2 = 12.6 cm.

  12. 12. Area 201.1 cm², circumference 50.3 cm

    Area = πr² = π × 8² = 201.1 cm². Circumference = 2πr = 2 × π × 8 = 50.3 cm.

Worked examples

Easy example

A rectangle is 13 cm by 15 cm. Find its perimeter and area.

  1. Perimeter = 13 + 15 + 13 + 15 = 56 cm.
  2. Area = 13 × 15 = 195 cm².
  3. Answer: Perimeter 56 cm, area 195 cm²
Medium example

A triangle has base 14 cm and height 4 cm. Find its area.

  1. Area = ½ × base × height.
  2. ½ × 14 × 4 = 28 cm².
  3. Answer: 28 cm²
Hard example

Find the area and circumference of a circle with radius 7 cm (to 1 d.p.).

  1. Area = πr² = π × 7² = 153.9 cm².
  2. Circumference = 2πr = 2 × π × 7 = 44 cm.
  3. Answer: Area 153.9 cm², circumference 44 cm

Interactive practice

Free, no account required — answer on screen or print it.

Common mistakes

What learners typically get wrong, and how to fix it.

  • Mixes up area and perimeter.

    Correction: Perimeter is a fence (around), area is grass (inside).

  • Uses the slanted side as the height of a triangle.

    Correction: Height must be at right angles to the base.

Teacher tips

  • · Draw shapes on squared paper and count squares first.

Parent tips

  • · Measure a room and work out how much carpet you'd need.

Real-life applications

  • · Carpeting a room, fencing a garden.

Assessment objectives

How mastery is evidenced, and which standards it maps to.

IB IB-673.1 — Mapped statement covering Introducing Area Under a Curve.EDEXCEL EDE-330.2 — Mapped statement covering Introducing Area Under a Curve.

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Frequently asked

Is this Grade 3 Introducing Area Under a Curve lesson really free?
Yes. Every lessons on FreeMathWorksheet is free to use, print and share — no account, no paywall and no watermark.
What should a learner already know before this?
Start with Definite Integrals. Each one has its own free lesson, worksheet and quiz.
How is the lesson sequenced?
Recognition first, then understanding, application, reasoning and finally mastery — the same ladder used across every free resource on the platform.
What comes next after Introducing Area Under a Curve?
Move on to Working with Area Under a Curve, Area Under a Curve in Context, Reverse Differentiation, Definite Integrals, which build directly on this idea.

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