Answer:
5. DBE and CBA both=48 degrees
6. a. scalene, right
b.isosceles, obtuse
c. scalene, acute
7. 50 degrees
8. im not completely sure how to do this one but ill check into it
Step-by-step explanation:
its a lot to explain, in 5 find p and plug it in.
in 6, just look at the sides and angles.
scalene- no sides equal
isosceles- 2 sides equal
equilateral- all sides equal
right- one 90 degree angle
acute- all acute angles (less than 90)
obtuse- one obtuse angle (more than 90)
7. add 90 and 40 to get 130. 180-130=50
8. im gonna look up how to do this one right now
The main identity you need is the double angle one for cosine:

We get

Expand the numerator to apply the identity again:




Finally, make use of the product identity for cosine:

so that ultimately,


Answer:
x = 12
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Sum the 3 given angles and equate to 180, that is
9x + 11 + 3x - 15 + 2x + 16 = 180, simplify left side
14x + 12 = 180 ( subtract 12 from both sides )
14x = 168 ( divide both sides by 14 )
x = 12
Answer:
The value of the second expression is 14, so the expressions are equivalent.
Step-by-step explanation:
x=5
6+2(5)-2=
6+10-2=
16-2=
14
The other expression also came out to be 14, so they are equivalent.