Question

Classify the triangle based on side lengths 5, 15, 19.

A right
B acute
C obtuse
D no triangle can be formed with given side lengths

Answer 1

To determine if the lengths can be a triangle, use the Triangle Inequality Theorem: One side of a triangle is less than the sum of the other two.

5 < 15 + 9 ?

9 < 5 + 15 ?

19 < 5 + 15 ?

Answer 2

It appears that these lengths can be the sides of a triangle.

Answer 3

I believe it would be obtuse? I may be wrong:/

Answer 4

There's a theorem for this. We don't have to guess. Hold on. @cwright150

Answer 5

alright thanks for all the help @Directrix

Answer 6

and @kali96748 thanks for the guess :)

Answer 7

Alright, Im sorry it would be Scalene because there are three different side lengths and Pythagoras theorem is not proved so it cant be a right

Answer 8

For an acute triangle, the square of the LONGEST side MUST BE LESS than the sum of squares of the other two sides.

For an obtuse triangle, the square of the LONGEST side MUST BE Greater than the sum of squares of the other two sides.

Answer 9

Indeed, which singles out scalene (;

Answer 10

@cwright150

Is 19^2 > 5^2 + 15^2

Answer 11

but scalene is not one of the choices so it is most likely acute

Answer 12

It is acute(;

Answer 13

@cwright150 Waiting for you to respond:

Is 19^2 > 5^2 + 15^2

Answer 14

yes
its 361>250

Answer 15

So, the triangle is obtuse.

Answer 16

:) thanks for explaining that.

Answer 17

If 19^2 < 5^2 + 15^2, then acute.

If 19^2 = 5^2 + 15^2, then right.

Answer 18

You are welcome.