Answer:
D. the incenter
Step-by-step explanation:
Hope this helps
By angle, you're a scalene triangle, and by angle, youre an acute triangle
The perimeter of a triangle is the sum of its side lengths.
The perimeter of the triangle is: 
<u>The sides of the triangle are:</u>
Side 1 = (8d - 3) cm
Side 2 = (6d + 2) cm
Side 3 = (7f + 8) cm
The perimeter (P) is calculated as:
P = Side 1 + Side 2 + Side 3
So, we have:

Remove brackets

Collect like terms


Hence, the perimeter of the triangle is: 
Read more about perimeters at:
brainly.com/question/6465134
Answer:
3
Step-by-step explanation:
Using listing:


No other factors are possible.
Hence, 1, 3, 7 and 21 are factors of 21.