Question 7 - Figure it out - Page 238, 239 - Chapter 9 Class 6 - Symmetry (Ganita Prakash)

Transcript

Question 7 (a) This is a picture of the new Parliament Building in Delhi. (a) Does the outer boundary of the picture have reflection symmetry? If so, draw the lines of symmetries. How many are they?Let’s enlarge it and check Question 7 (b) This is a picture of the new Parliament Building in Delhi. (b) Does it have rotational symmetry around its centre? If so, find the angles of rotational symmetry.We mark its center and check rotational symmetry Checking Rotational Symmetry Thus, in 1 full turn (i.e 360°) The figure is same as that of initial 3 times So, we say that figure has Rotational Symmetry of order 3 And, Angle of symmetry = (𝟑𝟔𝟎° )/(𝑶𝒓𝒅𝒆𝒓 𝒐𝒇 𝑹𝒐𝒕𝒂𝒕𝒊𝒐𝒏𝒂𝒍 𝑺𝒚𝒎𝒎𝒆𝒕𝒓𝒚) = (360° )/3 = 120° Thus, the figure would be same at angles 120° 120° × 2 = 240° 120° × 3 = 360° So, we write Angles of symmetry = 120°, 240°, 360°