📐 Triangle Area 📚 Grade 4 ⏱ 6 min
Triangle Area: Formula and Experiment
The triangle area formula (base times height divided by 2) is not abstract — it can be seen by cutting a rectangle in half.
A triangle is half a rectangle
Take a rectangle and draw a diagonal — you get two identical triangles. Each one's area is exactly half the rectangle's area.
💡 Anchor: cut a rectangle from paper, cut along the diagonal — stack the triangles on top of each other to see they match.
The area formula
Formula: A = (base × height) ÷ 2
A triangle with base 8 cm and height 5 cm: A=(8×5)÷2=20 sq cm
A triangle with base 8 cm and height 5 cm: A=(8×5)÷2=20 sq cm
FAQ
Does the formula work for any triangle?
Yes, for any — right, isosceles, or scalene.