Area of a right triangle
A right-angled triangle is drawn on a grid where each block is 1 cm². The student finds the area enclosed by its sides.
The base and height can be read off the grid, and the area is half of base × height: half the rectangle around it.
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What changes each time
- Corners on a 16 × 16 grid
- The right angle at the bottom left or bottom right
- A new triangle every time
More area, perimeter and volume practice
- Area by counting squares (Grade 2)
- Area and perimeter of a square (Grade 3)
- Area and perimeter of a rectangle (Grade 3)
- Area with half squares (Grade 3)
- Area of an L-shape (Grade 3)
- Perimeter of an L-shape (Grade 3)
- Draw a rectangle with a given area and perimeter (Grade 3)
- Missing side of a rectangle (Grade 4)
- Rectangle sides from a ratio (Grade 4)
- Area of an isosceles triangle (Grade 4)
- Area of a scalene triangle (Grade 4)
- Area of an irregular polygon (Grade 5)
- Missing triangle in a square (Grade 5)
- Volume by counting cubes (Grade 5)