Area of a Triangle
Establish the formulas for areas of rectangles, triangles and parallelograms, and use these in problem solving (ACMMG159 - Scootle)
- building on the understanding of the area of rectangles to develop formulas for the area of triangles
- establishing that the area of a triangle is half the area of an appropriate rectangle
- using area formulas for rectangles and triangles to solve problems involving areas of surface
Use the sliders (red dots) to change the size of the triangle/rectangle. Use the checkboxes (top left-hand corner) to show/hide the area of the rectangle and triangle.
Use formula: B x H (base x height) for surface area of a rectangle.
Use formula: 1/2 B x H (half [0.5] x base x height) for surface area of a triangle.
Can you see the relationship between the area of a triangle and a rectangle? (50-100 words)
Find the area of both rectangle and triangles for:
a) B = 6, H = 4
Rectangle Area =
Triangle Area =
b) B = 12, H = 10
Rectangle Area =
Triangle Area =
c) B = 20, H = 50
Rectangle Area =
Triangle Area =
Use the interactive platform to make and solve 5 of your own problems (you can be creative with your numbers).
a)
b)
c)
d)
e)