is a triangle with the sides measuring 12 cm, 15cm, and 28cm possible?

Question

how did you figure it out?

Answer 1

no, 12 + 15 < 28
any side of a triangle must be less than the sum of the other 2 sides

Answer 2

By the cosine law, it is not possible. draw a triangle so the angle A is between the 12cm and 15cm sides. then the opposite side is 28cm long. Find the angle A.

cos A = [15^2 + 12^2 - 28^2] / [2*15*12]
cos A = 1.15, which is impossible since -1 <= cos A <= 1.

Answer 3

To make a triangle, the two smallest sides need to add to BIGGER than the 3rd side.

Example 1: sides are 5, 8, 13

Not a triangle, since 5+8=13 (not bigger than 13)

Example 2: sides are 5, 8, 12

Yes, a triangle, since 5+8 =13, which is bigger than 12.

Answer 4

A triangle of sides w/ lengths a, b and c exists if and only if
a + b > c
b + c > a
c + a > b

or
A triangle of sides w/ lengths a, b and c (where c is the longest) exists if and only if
a + b > c

Since 28 is the longest,
c = 28
a = 12
b = 15

a + b >? c
12 + 15 >?28
27 (not>) 28
therefore there is no such triangle
^_^

Answer 5

no its not two sides added together on a triangle is greater than the other side that was not added

12+28>15
28+15>12
12+15<28

since 12+15=27 it is not greater than 28

Answer 6

considering the properties of a triangle,there is one property which says "any side's length should be less than sum of other 2 side's length" here if u see
12+15=27 which is less than 28.
hence it is not possible...

Answer 7

yes but it is not an equilateral triangle it is in fact an obtuse triangle

Answer 8

Don't think so! Two of the other sides are real short-ish!

Answer 9

I don't know
12square + 15square is not equal to 28square