MaTH hELP (1 Viewer)

[cUfffsxd]

kk i was studying and came across something, 2001 sc section 2 part b Q 79 which is:

"The longest side of a triangle is 10 cm. The perimeter of the triangle could be
(A) 18 cm (B) 20 cm (C) 22 cm (D) 28 cm"

kk i dont know the answers because they are not there, and there are 1 or more correct answers. Can anyone help me plz?

 

[muzeikchun852]

the answer is c and d..
becoz with 10cm as the longer side..
thats mean at least 20 cm for the perimeter..
which means be cannot be possible.

 

[jonowang]

C or D cos the longest side is less than the two other sides combined.

 

[cyclicpermutate]

kk i was studying and came across something, 2001 sc section 2 part b Q 79 which is:

"The longest side of a triangle is 10 cm. The perimeter of the triangle could be
(A) 18 cm (B) 20 cm (C) 22 cm (D) 28 cm"

kk i dont know the answers because they are not there, and there are 1 or more correct answers. Can anyone help me plz?

Let the sides of the triangle be where

By the triangle inequality,

 

[Amogh]

In a triangle, the sum of two sides HAS to be greater than the third.
So, for eg., 1,2, 4 : are not possible sides of a triangle as 1+2<4
Applying that we get:
The highest possible perimeter is 10+9+9=28 (d)
We can get 22 as a perimeter as well (10,9,3)
20 is not an answer as the possible values of 10, 5, 5 don't meet the criteria (5+5=10, not greater than 10)

 

[cUfffsxd]

Thx everyone, i was thinking a bit more complicated XD thanks heaps.

 

[Amogh]

Thx everyone, i was thinking a bit more complicated XD thanks heaps.

its the sc dude dont think too hard

 

[mitchy_boy]

its the sc dude dont think too hard

haha so true.

 

[jonowang]

just keep things simple, and dont stress too much mate. theres no point in over working mate, its the sc