A B C is a scalene (non-degenerate) triangle with integer side lengths. If A B = 2 and B C = 3 , what is the perimeter of triangle A B C ?
Note: A scalene triangle has no equal sides. A degenerate triangle has 0 area.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
The sum of the length of two sides of a triangle is always greater than the third side. Hence, third side of the triangle should be less than 3+2= 5. But we can't choose 3 and 2 as the above triangle is scalene. Therefore the remaining options are 1 and 4. We can't choose 1 as 1+2=3, which is equal to 3(the length of third side). Hence 1 is discarded and 4 is the third side. Hence, perimeter is 2+3+4= 9.
The measure of the third side is strictly between ∣ 2 − 3 ∣ = 1 and 2 + 3 = 5 . Since the triangle is scalene and has integer side lengths, the only possible length of the third side is 4 . Hence, the perimeter is 2 + 3 + 4 = 9 .
Here we see that the two sides of the triangle ABC are 2 and 3 therefore sum of the two side AB and BC=2+3=5 Now we know that sum of two sides of a triangle is greater than the third side therefore 5 is greater than the third side possibilities of the length of the third side=1 or 2 or 3 or 4 but the third side cannot be 2 or 3 because the triangle is scalene therefore the third side is either 1 or 4 but if the third side is 1 then 1+2=3 i.e. the sum of two sides of triangle ABC is equal to the third side this is not possible therefore the third side = 4 therefore AB=2 , BC=3 and CA=4 therefore perimeter of triangle ABC=2+3+4 =9 Ans: The perimeter of triangle ABC is 9
Firstly, by the triangle inequality, we see that the length of the third side (c) 1 < c < 5
Thus c = 2 , 3 , or 4 .
Since the triangle is scalene, c cannot equal to 2 or 3, else it would be isosceles.
Thus c = 4 .
Perimeter = 2 + 3 + 4 = 9
Call the length of the unknown side x.
From the triangle inequality we have 2+3>x, x<5 We also have x+2>3, x>1
As x is an integer, we have x=2,3,4
But 2,3 would repeat side lengths, so x must be 4.
Perimeter=2+3+4=9
a,b,c be sides with usual notations a=3 , c=2 a+c>b which implies 5>b 2,3 cannot be chosen as triangle is scalene and 1 does not satisfy triangle inequality 2+1=3 so 4 is the only choice left
as triangle is non-degenerate it can't have length of third side 0,1 or 5 because in these cases the third side lies on other sides. and length cannot be more than 5 because no non-degenerate triangle possible such that "sum of its two sides are less than or equal to third side". the possibility for third side is only 2, 3 or 4. as triangle is scalene so 2 and 3 not possible answers.so third side is 4. now 2+3+4=9 is perimeter.
Through the Triangle Inequality, the difference between 2 sides must not be more than the third side.
CA>AC-AB --> CA>1 AB>CA-BC --> 2>CA-3 --> CA<5.
Since ABC is scalene, CA could not be 2 or 3. Thus, CA is 4. Its perimeter is then 9.
We know that a triangle with side a, b, and c has a "trick" which a plus b is more than c, a plus c more than b, and b plus c more than a with a, b, and c are different. Since a is 2, b is 3, so 2 plus 3 more than c, c plus 3 more than 2, and c plus 2more than 3. So, c is 4.
Let C D = x . By the triangle inequality we get the next 3 inequalities:
3 + 2 > x , 2 + x > 3 , 3 + x > 2
The inequalities imply that 5 > x > 1 . As x is integer, it can only take the values 2 , 3 or 4 . But 2 and 3 are not possible, since the triangle is scalene.
Therefore x = 4 , and the perimeter is 2 + 3 + 4 = 9 .
easiest explanation, good show.
First of all, everyone should know that in any non-degenerate triangle, every side is smaller than the sum of the other two. This limits the length of A C to below 5 but above 1. Since it is also a scalene triangle, the only value of A C is 4. By adding 2, 3 and 4 together, you get an answer of 9.
The longest side of a triangle is less than the sum of its 2 other side. In this case, the longest possible side = 4, so perimeter = 2+3+4=9
Problem Loading...
Note Loading...
Set Loading...
In a triangle, the sum of the length any 2 sides must always be larger than the length of the 3rd.
Hence, the length of A C must be less than 5 and more than 1 .
Since A B C is a scalene triangle, A C cannot be of length 2 or 3 .
Since A B C has integer side lengths, A C must be of length 4 .
Therefore the perimeter is 2 + 3 + 4 = 9 .