Step-by-step explanation:
this is not an isoceles triangle.
anyway, we need to remember 2 things :
1. the sum of all angles in a triangle is always 180°.
2. the sum of all angles around a single point on a line is 360° (as this point wound be the center of an invisible circle). and as the line cuts this circle in half, the angles on one side of the line around this point is therefore 180°.
so, the internal angle Q is then
180 = 50 + 55 + Q
Q = 180 - 50 - 55 = 180 - 105 = 75°
the exterior angle x at Q is then
180 = Q + x = 75 + x
x = 180 - 75 = 105°
Answer:
C
Step-by-step explanation:
The quotient is 18
Using the law of cosine for Triangle KJL, we can write:
Using the values of k,j and l, we can write:
Rounding to nearest integer, the measure of angle J will be 48 degrees.
So option B gives the correct answer
Answer:
D
Step-by-step explanation:
Answer:
First, let's recall some usefull information:
- cot(x) = 1/tg(x) = cos(x)/sin(x)
- tan(x) = sin(x)/cos(x)
We also know that:
- cos(x - pi/2) = sin(x)
- sin(x - pi/2) = -cos(x)
Now we can use those relationships and get:
cot(x - pi/2) = cos(x - pi/2)/sin(x -pi/2) = sin(x)/-cos(x) = -tan(x)
So we have verified the identity, and explained step by step why the identity is true.
