<u>Answer:</u>
9. x = 12
10. x = 31
<u>Step-by-step explanation:</u>
9. Corresponding angles are equal, so technically you can move that (7x - 20) to be diagonal with the (4x + 16). Along with the corresponding angle, diagonal angles are equal to each other. Therefore you can set (7x - 20) equal to (4x + 16) to find x.
7x - 20 = 4x + 16
Solve
3x - 20 = 16
3x = 36
x = 12
Therefore x is equal to 12
<u>Check:</u>
4(12) + 16
= 64
7(12) - 20
= 64
10. All angles in a triangle have to add up to 180 degrees. Therefore, you can write your equation like this:
x + 2x + 25 + 2x = 180
Combine like terms
5x + 25 = 180
Solve
5x = 155
x = 31
Therefore, x = 31.
<u>Check:</u>
31 + 2(31) + 25 + 2(31) = 180
31 + 62 + 25 + 62 = 180
180 = 180
<em>I hope this helps!!</em>
<em>- Kay :)</em>
<em />
Answer:
12.1 cm
Step-by-step explanation:
Using the law of sines, we can find angle C. Then from the sum of angles, we can find angle B. The law of sines again will tell us the length AC.
sin(C)/c = sin(A)/a
C = arcsin((c/a)sin(A)) = arcsin(8.2/13.5·sin(81°)) ≈ 36.86°
Then angle B is ...
B = 180° -A -C = 180° -81° -36.86° = 62.14°
and side b is ...
b/sin(B) = a/sin(A)
b = a·sin(B)/sin(A) = 13.5·sin(62.14°)/sin(81°) ≈ 12.0835
The length of AC is about 12.1 cm.
_____
<em>Comment on the solution</em>
The problem can also be solved using the law of cosines. The equation is ...
13.5² = 8.2² +b² -2·8.2·b·cos(81°)
This is a quadratic in b. Its solution can be found using the quadratic formula or by completing the square.
b = 8.2·cos(81°) +√(13.5² -8.2² +(8.2·cos(81°))²)
b = 8.2·cos(81°) +√(13.5² -(8.2·sin(81°))²) . . . . . simplified a bit
Since triangle is isosceles, that means that unknown angles are equal. 180-72=108
108:2=54
So you’re answer would be: 54 degrees.
3.08 is the answer because:
1(1)+3(2)+4(3)+4(4)+1(5)=40
40/13 is about 3.08.
Step-by-step explanation:
there is no diagram attached
