Respuesta :
Answer:
AC ∈ {4, 5, 6, 7}
Explanation:
When two sides of a triangle are specified, the allowable values for the length of the third side are between the sum and difference of the given sides.
In ∆ACD, sides DA and CD are both given as length 4. Thus the possible range of values for side AC is 0 – 8. The extremes of this range result in ∆ACD having zero area, so we assume they are not of interest.
In ∆ACB, sides AB and BC are given as having lengths 3 and 6. Thus the possible range of values for side AC is 3 – 9. The extremes of this range result in ∆ACB having zero area, so we assume they are not of interest.
The integers that are in both ranges and that give triangles with non-zero area are ...
... AC ∈ {4, 5, 6, 7}