Triangle is attached below
The triangle is 12 by 10 by 8
Perimeter:
To find perimeter we add all the sides of the triangle
Perimeter P = 12 + 10 + 8 = 30 units
Semi perimeter:
Semi perimeter is half of its perimeter
We know P = 30
Semi perimeter s= = = 15 units
Area:
If we know the sides of the triangle then we use Heron's formula to find the area of the triangle
Where s= semi perimeter
a,b,c are the sides of the triangle
s= 15 units
a= 12 units
b= 10 units
c= 8 units
A= 39.7 square units