Area of this triangle?
A normal-level "Area" problem.For any slanted shape: box it in, then subtract the right triangles around it. With a grid this works on however complicated a polygon.
GivenEach grid square is 1 cm by 1 cm
Hints
- All three sides are slanted, so "base × height" is no use as it stands — and counting squares fails because the edges cut them in half.
- So take the smallest rectangle that boxes the triangle in: 5 across and 6 up, i.e. 30 cm². Every slanted side now sits inside it.
- Take the triangle out of the rectangle and three right triangles are left around it. Each one lines up with the grid, so you can read its base and height straight off.
- Work them out one by one. They total 16 cm².
- Subtract those three from the boxing rectangle: 30 − 16
Answer 14cm²
More "Area" problems
- Area of the inner triangle?
- Area of triangle DOA?
- Area of quadrilateral ABCD?
- Area of the overlap?
- Total area of the two crescents?
- Area swept by the square?