Geometry
Area
Area measures the space inside a 2D shape. Key formulas: Rectangle = lw, Triangle = ½bh, Circle = πr², Trapezoid = ½(b₁+b₂)h.
Watch & Learn
Watch a clear, friendly video explanation of Area:
Watch on YouTube →Opens a YouTube search for the best tutorial videos on this topic.
Worked Examples
Follow along with these step-by-step examples. Take your time — there's no rush!
Problem
Find the area of a triangle with base 10 and height 6
Step-by-Step Solution
A = ½ × base × height
A = ½ × 10 × 6 = 30
Answer
A = 30 square units
Problem
Find the area of a circle with radius 5
Step-by-Step Solution
A = πr²
A = π(5)² = 25π ≈ 78.54 square units
Answer
A = 25π ≈ 78.54 square units
Problem
Find the area of a trapezoid with bases 6 and 10, height 4
Step-by-Step Solution
A = ½(b₁ + b₂) × h
A = ½(6 + 10) × 4 = ½(16)(4) = 32
Answer
A = 32 square units
Problem
Find the area of a rectangle with length 15 and width 7
Step-by-Step Solution
A = l × w
A = 15 × 7 = 105
Answer
A = 105 square units
Problem
A circle has area 49π. What is its radius?
Step-by-Step Solution
A = πr² → 49π = πr²
r² = 49 → r = 7
Answer
Radius = 7 units
Your Turn — Practice Problems
Try all 5 problems on your own first. Write out your work — that's how it sticks!
💡 Tip: Don't peek at the answers until you've genuinely tried each one.
Area of rectangle: length 9, width 5?
Area of triangle: base 8, height 7?
Area of circle: radius 6?
Area of square with side 11?
Area of trapezoid: bases 4 and 8, height 5?
Area of triangle: base 14, height 10?
Area of circle: radius 10?
Area of rectangle: length 7, width 7?
A circle has area 16π. What is the radius?
Area of trapezoid: bases 6 and 14, height 8?
Area of triangle: base 20, height 3?
A square has area 144. What is the side length?
Finished all 12? Give yourself a pat on the back — then check your work!
Keep going — you're on a roll!
Every topic you master is another step on your journey.
Explore More Topics