Perimeter of rectangle = 2 × (length + breadth)
Area of rectangle = length × breadth
Perimeter of square = 4 × side
Area of square = side²
Perimeter of triangle = sum of all sides
Area of triangle = (base × height)/2
Perimeter of circle = 2 × π × radius
Area of circle = π × radius²
Volume of cube = side³
Volume of cuboid = length × breadth × height
Volume of cylinder = π × radius² × height
Volume of cone = (1/3) × π × radius² × height
Surface area of cube = 6 × side²
Surface area of cuboid = 2 × (length × breadth + breadth × height + height × length)

🪤 The 5 Mistakes That Cost Marks

Not converting units of measurement before calculation
Forgetting to use π = 22/7 for calculations involving circles
Not using correct formulas for perimeter and area of different shapes
Not taking care of significant figures during calculations
Not checking the units of the answer

✏️ 3 Solved PYQs

Question 1: Find the area of a triangle with base 5 cm and height 12 cm. Step 1: Identify the formula for the area of a triangle, which is (base × height)/2. Step 2: Plug ∈ the values of base and height into the formula: (5 × 12)/2. Step 3: Calculate the area: (5 × 12)/2 = 60/2 = 30 cm².
Question 2: Find the volume of a cuboid with length 8 cm, breadth 5 cm, and height 3 cm. Step 1: Identify the formula for the volume of a cuboid, which is length × breadth × height. Step 2: Plug ∈ the values of length, breadth, and height into the formula: 8 × 5 × 3. Step 3: Calculate the volume: 8 × 5 × 3 = 120 cm³.
Question 3: Find the surface area of a cube with side 6 cm. Step 1: Identify the formula for the surface area of a cube, which is 6 × side². Step 2: Plug ∈ the value of side into the formula: 6 × 6². Step 3: Calculate the surface area: 6 × 6² = 6 × 36 = 216 cm².

🧠 The One Thing Most Students Get Wrong

Most students get confused between the formulas for perimeter and area of different shapes, especially for circles and triangles.
They often forget to use the correct value of π (22/7) for calculations involving circles.
To avoid this mistake, it is essential to practice and memorize the formulas for perimeter and area of different shapes.

👁️ Ayush's Note

Always read the question carefully and identify the shape involved.
Use the correct formula for the shape and plug ∈ the given values.
Check the units of the answer and ensure that it is ∈ the required unit.
Practice, practice, practice - the more you practice, the more confident you will become ∈ solving mensuration problems.

🔁 Last 5 Minutes Box

Revision of formulas for perimeter and area of different shapes.
Quick practice of simple problems to build confidence.
Check the units of the answer and ensure that it is ∈ the required unit.
Read the question carefully and identify the shape involved.
Use the correct formula for the shape and plug ∈ the given values.

📝 Practice MCQs

1. What is the formula for the area of a triangle?

A) (base + height)/2

B) (base × height)/2

C) base + height

D) base × height

Answer: B) (base × height)/2.

2. What is the formula for the volume of a cuboid?

A) length + breadth + height

B) length × breadth + height

C) length × breadth × height

D) length + breadth × height

Answer: C) length × breadth × height.

3. What is the formula for the surface area of a cube?

A) 4 × side²

B) 5 × side²

C) 6 × side²

D) 8 × side²

Answer: C) 6 × side².

4. What is the formula for the perimeter of a circle?

A) π × radius

B) 2 × π × radius

C) π × diameter

D) 2 × π × diameter

Answer: B) 2 × π × radius.

5. What is the formula for the area of a circle?

A) π × radius

B) π × radius²

C) π × diameter

D) π × diameter²

Answer: B) π × radius².

🚀 Ready to Ace Your Exam?

Put your knowledge to the test! Take the free Practice Mock Test now and track your progress against thousands of students.

🎬 Watch video explanations on YouTube →

This post was curated by Jules, Exam Compass Bot, and edited for accuracy by Ayush.

📚 Related Topics

Continue your revision with these related guides:

Perimeter of rectangle = 2 × (length + breadth)
Area of rectangle = length × breadth
Perimeter of square = 4 × side
Area of square = side²
Perimeter of triangle = sum of all sides
Area of triangle = (base × height)/2
Perimeter of circle = 2 × π × radius
Area of circle = π × radius²
Volume of cube = side³
Volume of cuboid = length × breadth × height
Volume of cylinder = π × radius² × height
Volume of cone = (1/3) × π × radius² × height
Surface area of cube = 6 × side²
Surface area of cuboid = 2 × (length × breadth + breadth × height + height × length)

🪤 The 5 Mistakes That Cost Marks

Not converting units of measurement before calculation
Forgetting to use π = 22/7 for calculations involving circles
Not using correct formulas for perimeter and area of different shapes
Not taking care of significant figures during calculations
Not checking the units of the answer

✏️ 3 Solved PYQs

Question 1: Find the area of a triangle with base 5 cm and height 12 cm. Step 1: Identify the formula for the area of a triangle, which is (base × height)/2. Step 2: Plug ∈ the values of base and height into the formula: (5 × 12)/2. Step 3: Calculate the area: (5 × 12)/2 = 60/2 = 30 cm².
Question 2: Find the volume of a cuboid with length 8 cm, breadth 5 cm, and height 3 cm. Step 1: Identify the formula for the volume of a cuboid, which is length × breadth × height. Step 2: Plug ∈ the values of length, breadth, and height into the formula: 8 × 5 × 3. Step 3: Calculate the volume: 8 × 5 × 3 = 120 cm³.
Question 3: Find the surface area of a cube with side 6 cm. Step 1: Identify the formula for the surface area of a cube, which is 6 × side². Step 2: Plug ∈ the value of side into the formula: 6 × 6². Step 3: Calculate the surface area: 6 × 6² = 6 × 36 = 216 cm².

🧠 The One Thing Most Students Get Wrong

Most students get confused between the formulas for perimeter and area of different shapes, especially for circles and triangles.
They often forget to use the correct value of π (22/7) for calculations involving circles.
To avoid this mistake, it is essential to practice and memorize the formulas for perimeter and area of different shapes.

👁️ Ayush's Note

Always read the question carefully and identify the shape involved.
Use the correct formula for the shape and plug ∈ the given values.
Check the units of the answer and ensure that it is ∈ the required unit.
Practice, practice, practice - the more you practice, the more confident you will become ∈ solving mensuration problems.

🔁 Last 5 Minutes Box

Revision of formulas for perimeter and area of different shapes.
Quick practice of simple problems to build confidence.
Check the units of the answer and ensure that it is ∈ the required unit.
Read the question carefully and identify the shape involved.
Use the correct formula for the shape and plug ∈ the given values.

📝 Practice MCQs

1. What is the formula for the area of a triangle?

A) (base + height)/2

B) (base × height)/2

C) base + height

D) base × height

Answer: B) (base × height)/2.

2. What is the formula for the volume of a cuboid?

A) length + breadth + height

B) length × breadth + height

C) length × breadth × height

D) length + breadth × height

Answer: C) length × breadth × height.

3. What is the formula for the surface area of a cube?

A) 4 × side²

B) 5 × side²

C) 6 × side²

D) 8 × side²

Answer: C) 6 × side².

4. What is the formula for the perimeter of a circle?

A) π × radius

B) 2 × π × radius

C) π × diameter

D) 2 × π × diameter

Answer: B) 2 × π × radius.

5. What is the formula for the area of a circle?

A) π × radius

B) π × radius²

C) π × diameter

D) π × diameter²

Answer: B) π × radius².

🚀 Ready to Ace Your Exam?

Put your knowledge to the test! Take the free Practice Mock Test now and track your progress against thousands of students.

🎬 Watch video explanations on YouTube →

This post was curated by Jules, Exam Compass Bot, and edited for accuracy by Ayush.

📚 Related Topics

Continue your revision with these related guides: