The area of a triangle could be determined using the following formula
![\boxed{a= \frac{1}{2} \times b \times h}](https://tex.z-dn.net/?f=%5Cboxed%7Ba%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%20b%20%5Ctimes%20h%7D)
plug in the numbers
![a = \frac{1}{2} \times 21 \times 12](https://tex.z-dn.net/?f=a%20%3D%20%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%2021%20%5Ctimes%2012%20)
![a = \frac{1}{2} \times 252](https://tex.z-dn.net/?f=a%20%3D%20%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%20252)
![a= \frac{252}{2}](https://tex.z-dn.net/?f=a%3D%20%5Cfrac%7B252%7D%7B2%7D%20)
a = 126
The area of the triangle is 126 square meters
Answer is C.
For every option, sub in the value and find the answer that matches the equation!
Example for option A, F(x) = x + 4 and G(x) = x²
G(F(x)) = G(x + 4) ーー> sub in the value of F(x)
Let's take the subbed in value, (x + 4) as x, and this x will be the x for G(x).
∴ Since G(x) is x²
G(x + 4) = (x + 4)² ーー> remember (x + 4) is represented as x.
= x² + 16
∴ You know that the answer is not A, do this for all options and you'll find the answer, C!
1) 6x
2) 2x + 4
3) 5y + 11
hope this helps!
If his water to cement ratio is 20 to 30, this means that if he uses 20 liters of water, he'd use 30 liters of cement.
The total mixture would then be 20+30=50 liters.
and the water would be 20/50=0.4 or 40% of the total mixture.