Free powerpoint to teach the topics of Area and Perimeter to elementary school kids aspiring to compete in math contests such as the NLMC and Math Kangaroo

1. Topic 1.
Area and
Perimeter
WEEK 1. JUL. 5 TO JUL. 11

2. Area and Perimeter

3. Definition of Area:
The area of a two-dimensional shape is the space
occupied by the shape

4. Definition of Perimeter:
The perimeter of a two-dimensional shape is the
total distance that it takes to go around the shape.

5. Finding The Perimeter of Rectangles and Triangles
► Perimeter of Rectangles:
P= 2l(length) + 2w(width)
Squares have all sides equal,
while rectangles don’t have to
have equal sides.
► Perimeter of Triangles:
P= a+b+c
Equilateral Triangles have 3
equal sides, isosceles triangles
have 2 equal sides, and scalene
triangles don’t have equal sides

6. Perimeter example problem

7. Finding The Area of Rectangles and Triangles
► Area of Rectangles:
A= l(length) x w(width)
► Area of Triangles:
A= ½ x b(base) x h(height)

8. Example Area Problem

9. Example Area Problem
Try this one!

10. Example Area Problem
What are the areas of these triangles?

11. An angle is between 2 lines, and it is the measure of how far they are apart.
These are some types of angles:
What is an angle?

12. ► There are 360 degrees in a full circle.
► The angles in a triangle ALWAYS sum to 180
► The angles of a rectangle and square are always 90
Properties of angles

13. ► A straight line is half of a circle, so it contains 180 degrees
► If you have 2 straight lines, vertically opposite angles are
equal.
Properties of angles

14. ► If you have a set of parallel lines, and a line going through
them, angles 1 3 5 and 7 are equal and 2 4 6 and 8 are
equal.
Properties of angles

15. In this image, what is the missing angle? Angles marked by a
square are always right angles.
Angles Practice

16. Find the measure of marked
angles A and B.
Angles Practice

17. ► Just like you can sort triangles by their side length, you can
also sort them by their angles!
Triangles by angles

18. Food for Thought
Question
How do you prove that base x
height x ½ is the area for
obtuse triangles?

19. Circles
The area of a circle is A=πr2, where π is 3.141592654… and r
is the distance from the center of the circle to the edge.
The area of a sector of a circle, like the one in the top right,
is the angle divided by 360 multiplied by the area of the
whole circle.
The perimeter of a circle, called the circumference, is 2πr.

20. Circle Practice Problem
Try to solve for the area
of the blue part.

21. Time to work on the handouts!
Take the handouts that you printed out at home and using the
concepts that we learned today, start working on them. If you don’t
finish that’s okay, you can finish it at home.