area of triangle

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Slide 1: Slide
MathSecondary EducationAge 11

This lesson contains 24 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 45 min

Items in this lesson

Slide 1 - Slide

Slide 2 - Slide

Triangle

Slide 3 - Mind map

Draw the height of the following triangles.

Base
Base
Base

Slide 4 - Slide

Which letter indicates the triangle's height ?

Slide 5 - Open question

Look at the triangle's base. Which letter indicates the height?

Slide 6 - Open question

If N is the base of the triangle, which letter represents the height?

Slide 7 - Open question

A gardener wants to level a triangular garden with grass. Its base and height are 150m and 50m respectively. If the cost of levelling the garden is Rs.100 per sq. m. Find the cost . (SDG11)

Slide 8 - Slide

Area of triangle

Slide 9 - Slide

Slide 10 - Slide

Activity sheet (Area of Triangle)

Cut along the diagonal to separate the parallelogram into two triangular pieces.




Compare the area of parallelogram and the triangle and complete the activity sheet.
1. What is the formula for Area of Parallelogram?
2. What is the relation between the area of the parallelogram and the area of one triangle?
3. What is the formula for Area of triangle ?





Slide 11 - Slide

Area of the Traingle=

Slide 12 - Open question


LO: Develop the formula for finding the area of a triangle.

Area of the Triangle = ½ x base x height






Slide 13 - Slide

Slide 14 - Link

Slide 15 - Slide

Slide 16 - Slide

Task1

A triangle has a base length of 14 cm and its perpendicular height is 9cm. Find the area of the triangle.

Task 2


The area of a triangular-shaped garden is 72 sq.m and the height is 24m. Find the base

Task 3
Shown below is a wall. Calculate the area of the wall.



Slide 17 - Slide



1.The formula for finding the area of triangle=
2.Find the area of the triangle whose base is 12m and height is 8m


TextO: Apply the concept to solve problems.

Slide 18 - Open question

Slide 19 - Slide


What can you say about the areas of the following triangles?

LO: Apply the concept to solve problems.

Slide 20 - Slide

The base and the height of Triangle A are half the base and the height of Triangle B. How many times greater is the area of Triangle B?

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Slide 24 - Slide