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Triangle Area

Discovering the formula for the area of a triangle

Publisher: Texas Instruments UK

Editor: Barrie Galpin

Author: Jon Skinner

Topic:  Mathematik

Tags  Dreieck ,  Fläche

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 cm2: 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'.

Publisher specific license