CBSE Class 8 Mathematics
Question 5 of 12
Proportional Reasoning 2 — Question 5
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Question Can you construct a triangle with sidelengths in the ratio 1 : 3 : 5? Why or why not?
For a triangle to exist, it must satisfy the triangle inequality theorem, which states: The sum of any two sides of a triangle must be greater than the third side. Let’s take Side 1 = 1 cm Side 2 = 3 cm Side 3 = 5 cm 1. 1 + 3 < 5 ⇒ 4 > 5 (No) 2. 1 + 5 > 3 ⇒ 6 > 3 (Yes) 3. 3 + 5 > 1 ⇒ 8 > 1 (Yes) Since the first condition fails (1 + 3 = 4 < 5) We can’t construct a triangle with these sidelengths. 3.5 A Slice of the Pie Figure It Out (Pages 62-63)