1. DIFFERENT GEOMETRICAL SHAPES Rectangle Triangle

2. Square Rectangle Oval ( ellipse ) Circle

3. Angles A B C R S T U Q L M N O P Angles A,B,C are RIGHT ANGLES Right Angle : An angle of measure 90 is called right angle. Angles Q,R,S,T,U are obtuse angle Obtuse Angle : An angle of measure between 90 and 180 is called obtuse angle. Fig-1 Fig-2

4. In fig-2 angles L,M,N,O,P are ACUTE ANGLES ACUTE ANGLES : An angle of measure < 90 is called acute angle Acute angle Obtuse angle Right angle

5.  Identify the angles and write their name A B CD E F ACTUE ANGLES OBTUSE ANGLES RIGHT ANGLES

6. 2ND ShapesNo. of Right Angles No. of Acute Angle s ( Less than ) right angle No. of Obtuse Angle ( more than ) right angle 520 032 021

7. EXERCISE -1  Fill in the blanks…….. a.A right angle is equal to ( 90° ) b.An acute angle is less than ( 90° ) c.An obtuse angle is more than (90° ) and less than (180° ) d.⅟ 2 of a right angle is ( 45° ) e.2 right angle is (180° )

8. EXERCIS-2 1.Draw angles of the following measures. and write their name. A.45° B. 60° C. 90° D.120° 2.Draw One acute angle, one obtuse angle and one right angle of any measure 3. 3. Define acute angle,obtuse angle and Right angle.

9. Find : How many right angles are there in the given figure? Solution: The right angles in the given figure are: Thus, there are 14 right angles in the given figure.

10. 2: Which angle is represented by the following figure? Solution: We know that in an acute angle, one arm is bent towards the other arm. Thus, the angle represented by the given figure is acute.