Answer:
Option C. 15 cm
Step-by-step explanation:
The correct question is
A triangle has two sides that measure 8.7 cm and 12.3 cm. Which could be the measure of the third side?
A. 2.6 cm
B. 3.6 cm
C. 15 cm
D. 21 cm
we know that
The Triangle Inequality Theorem states that the sum of any 2 sides of a triangle must be greater than the measure of the third side
Analyze two cases
Let
x ----> the length of the third side
First case
x+8.7 > 12.3
x>12.3-8.7
x> 3.6 cm
Second case
12.3+8.7 > x
21 > x
Rewrite
x < 21 cm
look at the angles. they all ad up to 180 degrees devide that by 9, and there you go!
5
is their any way I can get some more info on this problem