What you’ll learn
Find area of triangles.
Key idea
A triangle has half the area of the matching base-height rectangle.
Match base with perpendicular height; inverse lengths require doubling area first, while a rectangle product is twice the triangle area.
Worked example
Enter the exact value or ordered values in the format requested below.
A triangle has base 3 cm and perpendicular height 6 cm. Enter its exact numerical area in square centimeters.
- The base 3 cm pairs with the perpendicular height 6 cm.
- A=bh/2=3×6/2=9 square centimeters.
Answer: 9
Quick Check
Evaluate a worked attempt at find area of triangles, identify the first invalid step, and provide the correction.
For a triangle with base 5 cm and perpendicular height 9 cm, a student writes Step 1: A=bh/2. Step 2: A=5×9=45 cm². Locate the first invalid step and correct the area.