JC10idn
Answered

IDNStudy.com, ang iyong gabay para sa malinaw at eksaktong mga sagot. Sumali sa aming interactive na platform ng tanong at sagot para sa mabilis at eksaktong tugon mula sa mga propesyonal sa iba't ibang larangan.

How to know if the lengths may form a triangle? For example. I have 3 cm, 10 cm, 15 cm sticks, will it form a triangle? How to guess/predict just with the
info's about the lengths? not by trying it in actual.


Sagot :

Since triangle or trigon has three sides, let:

a = side 1
b = side 2
c = side 3

If a and b are the two sides, then, to form a triangle the third side must satisfy the condition:
(a - b ) < c < a + b

Side c must be greater than the difference of sides a and b, but less than the sum of a  and b.


Given:
Option 1:
Side a = 3 cm
Side b = 10 cm
Side c = 15 cm

(10-3) < 15 < (3+ 10)
        7 < 15 < 13       ⇒    False
                                  ⇒   The third side must be
                                        {8, 9, 10, 11, 12}, 
                                         not {15}

Option 2:
Side a = 10 cm
Side b = 15 cm
Side c = 3 cm

(15-10) < 3 < (10 + 15)
      5     < 3 <   25   ⇒   False
                               ⇒   The third side must be
                                      {6, 7, 8, 9, 10, ..., 23, 24, 25},
                                      not {3}

Option 3:
Side a = 15 cm
Side b = 3 cm
Side c = 10 cm

(15-3) < 10 < (15 + 3)
     12   < 10 < 18       ⇒   False
                                  ⇒   The third side must be
                                         {13, 14, 15, 16, 17}
                                         not {10}