Answer:
see explanation
Step-by-step explanation:
Using the sum/ difference → product formula
cos x - cos y = - 2sin(
)sin (
)
sin x - sin y = 2cos (
)sin (
)
Given
(cosA - cosB)² + (sinA - sinB )²
= [ - 2sin(
)sin(
) ]² + [ 2cos(
)sin(
) ]²
= 4sin² (
)sin² (
) + 4cos² (
)sin² (
)
= 4sin² (
)[ sin² (
) + cos² (
) ← sin²x + cos²x = 1
= 4sin² (
) × 1
= 4sin² (
) = right side ⇒ proven
There exist a similar question where b = 68 instead of 6. First, determine the measure of the third angle, angle C,
m∠c = 180 - (55° + 44°) = 81°
Let x be the side AB, that which is opposite to angle C. Through the Sine Law,
68 / sin 44° = x / sin 81°
From the equation, the value of x is equal to 96.68. Thus, the answer is letter B.
Step-by-step explanation:
EXAMPLE OF SURFACE AREA
1/2 × (30×4) × 39 + (30×30)
= 60 × 39 + 900
= 2340 + 900
= 3240
The perimeter, by definition, is the outside measure of that figure. MN and LM are the same length and LK and NK are the same length....we just need to find the lengths! Use the distance formula to find the distance between the 2 points:

For the segment MN, use the coordinates of M as your x1, y1, and use the coordinates of N for x2, y2:

which simplifies to

which is

So that is the length of both MN and LM. So far our perimeter is

Now let's use the same formula to find out the length of one of the longer segments:

which simplifies down to

which is of course

Since we have 2 of those lengths,

So our perimeter is, in the end,

That's the third choice down