Ctrl+k

Find area of triangles

Area of a triangle is determined by A=12bhA=\tfrac12 bh, where bb is a chosen base and hh is the perpendicular distance to that base, not necessarily a slanted side. This relationship can be reasoned from a parallelogram or rectangle and applied with whole-number, decimal, or simple fractional measurements, recording answers in square units; Heron’s formula, trigonometric methods, and other advanced cases are not included.

Detailed Explanation: Find area of triangles

To find the area of a triangle, use:

A=12bhA=\frac{1}{2}bh
  • bb is the length of the chosen base.
  • hh is the perpendicular height—the distance straight up or down from the base to the opposite vertex.
  • The height is not always a slanted side.
  • Area is written in square units.

Think of a triangle as half of a parallelogram or rectangle with the same base and height.

Example: Find the area of a triangle with a base of 8 cm8\text{ cm} and a perpendicular height of 5 cm5\text{ cm}.

  1. Identify the measurements:

b=8 cm,h=5 cmb=8\text{ cm}, \qquad h=5\text{ cm}

  1. Substitute them into the formula:

A=12(8)(5)A=\frac{1}{2}(8)(5)

  1. Multiply:

A=12(40)=20A=\frac{1}{2}(40)=20

  1. Include square units:

20 cm2\boxed{20\text{ cm}^2}

The area of the triangle is 20 square centimeters\boxed{20\text{ square centimeters}}.

Learn by doing: Find area of triangles

Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill

    Practice with unlimited practice problems

    Area of an Obtuse Triangle - On Grid - Image to Area

      ?