Answer:
Option C is correct
Step-by-step explanation:
Given: A plane is descending onto the runway with an angle of depression of 55°. Also, it has 2.8 miles to go before landing.
To find: current altitude of the plane
Solution:
Consider the attached image.
In ΔABC,
(Alternate interior angles)
For any angle
,
= side opposite to angle/side adjacent to angle

Put 

So, the current altitude of the plane is 4 miles.
C = 4M + 5
4M = C - 5
M = (C - 5)/4
answer is D. Last one.
Answer:
Step-by-step explanation:
a+b+c=0, a+b=-c,a+c=-b, b+c=-a
(a+b+c)^3=(a+b+c)^2*(a+b+c)=(a^2+b^2+c^2+2ab+2ac+2bc)*(a+b+c)=
a^3+ab^2+ac^2+2a^2b+2a^2c+2abc+a^2b+b^3+bc^2+2ab^2+2abc+2b^2c+a^2c+b^2c+c^3+2abc+2ac^2+2bc^2=a^3+b^3+c^3+3a^2b+3a^2c+3ac^2+3ab^2+3bc^2+3b^2c+6abc=
a^3+b^3+c^3+3a^2*(b+c)+3c^2(a+b)+3b^2(a+c)+6abc=
a^3+b^3+c^3+3a^2*(-a)+3c^2*(-c)+3b^2*(-b)+6abc=
a^3+b^3+c^3-3a^3-3c^3-3b^3+6abc=
6abc-2a^3-2b^3-2c^3=2(3abc-a^3-b^3-c^3)=
2*[3abc-(a^3+b^3+c^3)]=0
so 3abc-(a^3+b^3+c^3)=0
so a^3+b^3+c^3=3abc
Answer: C) exactly one triangle
<u>Step-by-step explanation:</u>
Given: ∠A = 45°, ∠B = 65°, side c = 4 cm
By the Triangle Sum Theorem, ∠C = 70°
Now you have a proportion so you can use the Law of Sines to find the exact length of side a and of side b.

Thus, there is exactly one triangle.