Example 5 (Page 60) - Chapter 3 Class 8 - Proportional Reasoning-2 (Ganita Prakash II)

Transcript

Example 5 (Page 60) Construct a triangle with angles in the ratio 1 : 3 : 5.Let’s consider a triangle Here, the thing to keep in mind is Sum of angles of a triangle = 180° Now, the ratio of angles are 1 : 3 : 5 First, we add up Total Parts Total parts = 1 + 3 + 5 = 9 Now, we can write angles as ∠ A = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠 𝑜𝑓 ∠ 𝐴)/(𝑆𝑢𝑚 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠) × Sum of angles = 𝟏/𝟗 × 180° = 20° ∠ B = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠 𝑜𝑓 ∠ 𝐵)/(𝑆𝑢𝑚 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠) × Sum of angles = 𝟑/𝟗 × 180° = 60° ∠ C = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠 𝑜𝑓 ∠ 𝐶)/(𝑆𝑢𝑚 𝑜𝑓 𝑝𝑎𝑟𝑡𝑠) × Sum of angles = 𝟓/𝟗 × 180° = 100°