**1. Perpendicular Bisectors and Angle Bisectors**

- Use of compass: center, radius, pin leg, and drawing leg
- To draw a circle
- To mark off or copy a line segment
- How to draw a
**perpendicular bisector of a line segment**? - Any point on the perpendicular bisector of a line segment is equidistant from the two end points of the segment.

**2. Angle Bisectors**

- A ray AZ divides <BAC into two equal angles, <BAZ and <CAZ. The ray is called
**the angle bisector**of <ABC - How to draw an angle bisector?
- Any point on the angle bisector of an angle is equidistant from the two sides of the angle.

**3. Class work**

- Construct/draw circles, triangles, angles, equal line segments
- construct /draw perpendicular bisectors of line segments
- construct/draw angle bisectors of angles

**4. Classification of Triangles**

- The number of equal sides in the triangle:
**scalene triangle**– no equal sides;**isosceles triangle**– two equal sides;**equilateral triangles**– three equal sides - The type of angles of the triangle:
**acute-angled triangle**– all angles are acute;**right-angled triangle**– one of the angles is a right angle;**obtuse-angled triangle**– one of the angles is an obtuse angle - Is an equilateral triangle also an isosceles triangle?
- Is it Possible to draw a triangle with more than one obtuse angle?
- Can a scalene triangle be an acute-angled, right-angled or obtuse-angled triangle?
- All the three angles in a scalene triangle are different size
- The angles opposite the equal sides of an isosceles triangle are equal
- All the three angles in an equilateral triangle are equal in size

**5. Quadrilaterals**

- A closed plane figure with four straight sides joined by four vertices is called a quadrilateral
- Vertices, diagonals
- Properties of special quadrilaterals
- Parallelogram: 2 pairs of parallel and equal opposite sides
- Rectangle: all angles are right angles
- Rhombus: all sides are equal, diagonals are perpendicular to each other
- Square: all sides are equal, all angles are right angles
- Trapezoid: 1 pair of parallel sides

**6. Home Work:**

**Handout:**- Two pages

**Workbook:**- Page 48-50: 12, 13, 14,15,16