Tuesday 9th February 2021
Complete the quick maths starter.
DO NOT SPEND MORE THAN 10 MINUTES ON THIS ACTIVITY
Remember, your maths lesson should only last 1 hour,
unless you want to do more.
Please write the date and WALT at the top of your page.
WALT find the area of triangles ( right angled triangles)
Yesterday, we were counting squares to work out the area of triangles.
Today we are going to start thinking about other ways we can work out the area of a triangle.
last week, when we were working on the area of rectangles, we used the formula
length x width = area or L x W = A
If you know how to calculate the area of a rectangle, you can find the area of a triangle with no problems!
The area of a triangle is always half the area of a rectangle that has the same height and width.
This is because a triangle can always fit into a rectangle twice, no matter the shape of the triangle.
This video helpfully sums this up. Give it a watch.
So the formula we could use to find the area of a triangle is:
(base x height) ÷ 2
You can also write the formula as:
½ x base x height
They both give you the exact same answer since multiplying by a half is the same as dividing by 2.
Remember perpendicular is when lines meet at a right angle.