Question

Which set of numbers can represent the side lengths, in millimeters, of an obtuse triangle?
A. 8, 10, 14
B. 9, 12, 15
C. 10, 14, 17
D. 12, 15, 19

Answer 1

An obtuse triangle has one angle greater than 90

 

Using Pythagoras Theorem, we can test these triangles. We get the sum of 

the squares of the two shorter sides and compare with the square of the 

longer side.

A. 8, 10, 14

164 < 196 (Obtuse)


B. 9, 12, 15
225 = 225 (This is right-angled)

C. 10, 14, 17
296 > 289 (Not obtuse)


D. 12, 15, 19
369 > 361 (Not obtuse)

The correct answer is A

Answer 2

Answer:

Step-by-step explanation:

An obtuse triangle has one angle greater than 90

Using Pythagoras Theorem, we can test these triangles. We get the sum of

the squares of the two shorter sides and compare with the square of the

longer side.

A. 8, 10, 14

164 < 196 (Obtuse)

B. 9, 12, 15

225 = 225 (This is right-angled)

C. 10, 14, 17

296 > 289 (Not obtuse)

D. 12, 15, 19

369 > 361 (Not obtuse)

The correct answer is A