Answer: c. (1/2) bc sin A
<u>Step-by-step explanation:</u>
You can find the area of a triangle using trigonometry if you know the lengths of two sides and the measure of the included angle using the following formula:

Answer:
C
Step-by-step explanation:
In the attached file
Answer:
By definition, the derivative of f(x) is

Let's use the definition for 

Then, 
-1 / 7 = x
You need to combine the 2x and 5x then devise the 7x from -1
answer is C. 252 ft^2
split the figure into two pieces and first figure out the rectangle (shown in turquoise).
If you multiply the width and length (18*6) you should get 108.
Then figure out the trapezoid (in magenta). the formula is (a+b)/2*h where a and b are the bases and h is the height. the bases are given, 6 and 18. to find the height, subtract the entire figure's height by 6, which is 18-6 and gives us 12. so the formula converted to this problem is (6+18)/2*12. simplify parenthesis and get 24/2*12. 24/2=12, so multiply 12*12. The area of the trapezoid is 144. Add the areas of both figures together and get 252.