Answer:
x = 17
Area = 10,362units²
Explanation
Given the sides of the triangle
S1 = 9x+4
s2 = 8x-4
S3 = 4x+17
Perimeter of the triangle is the sum of all the sides
P = S1+S2+S3
374 = 9x+4+8x-4+4x+17
374 = 21x+17
21x = 374-17
21x = 357
x = 357/21
x = 17
Hence the value of x is 17
Area of the triangle is 1/2bh
A = 1/2bh
b is the base
h is the height
Let the base be 9x + 4 and height be 8x-4
b = 9x+4
b = 9(17)+4
b = 153+4
b = 157units
h = 8x-4
h =8(17)-4
h = 136-4
h = 132
Area = 1/2 * 157 * 132
Area = 157*66
Area = 10,362units²