##### Triangle Area

Discovering the formula for the area of a triangle

Publisher: Texas Instruments UK

Editor: Barrie Galpin

Author: Jon Skinner

Topic: Matematik

In this activity students move between a geometry and a spreadsheet page to explore the formula for the area of a triangle. The base, height and area of the current triangle can be captured to the spreadsheet page by pressing **ctrl** with the decimal point. Half the product of the base and height is also calculated.

They then move back to the geometry page, drag the clear vertex point to form a different looking triangle and add its data to the spreadsheet. They are encouraged to look for connections in the calculated values.

Various multi-choice questions then follow on the handheld. Feedback on each question is readily available by means of the menu button.

On page 1.10 a second activity asks students to draw and find areas of scalene, isosceles and right-angled triangles.

Students are then required to draw five triangles tall with an area of 18 cm^{2}: they can check these on an integer grid on page 1.14.

The final few pages provide possible plenary acivities including problems as well as 'Assessment for Learning'.