1819 G2X §8.4 & 8.5

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Which exercises/theories should we discuss on the board?

Match each shape and formula with the right name

Triangle

Parallelogram

Trapezium

Perimeter

The perimeter of a figure 

is the sum of all the sides.

Circles

The point in the middle of a circle is 

called the centre.

The distance from the centre to the edge 

of the circle is called the radius.

The line that divides the circle into two 

semicircles is called the diameter, this is twice the radius.

Circumference of a circle

The perimeter of a circle is called the circumference.

The formula to calculate the circumference of a circle is:

(π is pronounced "pi" and π≈3.14)

You can find π on your calculator:

Area of a circle

The formula for the area of a circle is:

Example

What is the circumference of this circle?

What is the area of this circle?

Example

What is the circumference of this circle?

What is the area of this circle?

Example

A circle has an circumference of 20.

What is the diameter of the circle?

What is the radius of the circle?

What is the area of the circle?

Example

A circle has an circumference of 20.

What is the diameter of the circle?

What is the radius of the circle?

What is the area of the circle?

Homework

HW Tuesday:

§8.4: NOT 22, 23. Make all other exercises from your chosen path.

§8.5: NOT 29, 30. Make half the other exercises from your chosen path.

Correct your answers.

HW Monday (Friday is Sport's day):

§8.5: Complete the rest of the exercise from your chosen path.

§8.6: Make 36, 37, 38, 40, 42 (not 39 and 41)

Correct your answers.