<u>Given</u>:
Let A denote the angle of the given triangle which measures ∠A = 81°
Let B denote the angle which measures ∠B = 40°
The length of the side a = x.
The length of the side b = 7 cm.
We need to determine the value of x.
<u>Value of x:</u>
The value of x can be determined using the law of sine formula.
Applying the law of sine, we have;
Substituting the values, we have;
Simplifying, we get;
Cross multiplying, we have;
Thus, the length of the side x is 10.8 cm.
10+10=20 = length
20 + 18 = 38 width = 18 or 9 on each side
10 x 9 = 90
Answer 90
Answer:
A = 140
Step-by-step explanation:
Area of a triangle:
A = 1/2bh
Given:
b = 20
h = 14
Work:
A = 1/2bh
A = 1/2(20)(14)
A = 10(14)
A = 140
The answer would be the first choice. 
Explanation: The reason for this is that the question was pretty much just asking what the area of the resulting two-dimensional cross section would be -the shape in gray- (which can be found by using the formula 
. To add on, since the dimensions of the shape are already given (5 and 3) all you've to do is multiply: 3*5=15
That's how you get to the answer.
