Area of figuresTriangles
Name: Date:
Find the area. Lengths are in cm; the dashed line is the height.
1 cm²
2 cm²
3 cm²
4 cm²
5 cm²
6 cm²
7 cm²
8 cm²
Area of a triangle worksheets
The triangle is half of the rectangle around it, and the one number that decides its area is the perpendicular height — never the slant side. These free printable worksheets drill triangles alone, with that height drawn as a dashed line.
Kid stuck on one? You don’t just get the sheet.
Area of a triangle
The answer key prints on a separate page.
What's on this sheet
This sheet cuts one figure out of the mixed area page, which hands a child triangles, parallelograms, and trapezoids in turn. Here every question is a triangle, so a child practices the halving step until it is automatic before the harder job of choosing between formulas arrives.
Why this sheet works
The height is dashed and carries a right-angle mark where it meets the base, and no slant side is ever labeled. That is the mistake this standard is about: a child who reaches for the sloping edge gets a number that is too big. Read the dashed line first, multiply it by the base, then take half.
How this one works
One question from this sheet, worked through a step at a time.
Area of a 13 by 8 triangle
- A triangle. Two of its numbers matter and they are not the two longest lines — find them before working anything out.
- The base is the side it stands on: 13 cm.
- The height is the DASHED line — straight up from the base, at a right angle to it: 8 cm. It is not the sloping side, even though the sloping side is longer and is written right next to it.
- Now the halving. Turn a second copy of the triangle upside down against this one and the two together make a parallelogram — 13 × 8 = 104. The triangle is exactly half of it.
- So half of 104 is 52 square cm.