Answer:
$18
Step-by-step explanation:
Given:
6.4x - 2.1x = 77.4
Where,
x = cost of sheet metal per square foot
How much does sheet metal cost per square foot?
6.4x - 2.1x = 77.4
4.3x = 77.4
Divide both sides by 4.3
x = 77.4 / 4.3
= 18
x = $18
Sheet metal per square foot cost $18
9+12>18
12+18>9
9+18>12
So, yes. A triangle can be formed by the given angles.
The answer is 678.09 plus 804
