Answer:
first option: Harulo is correct because the angle is coterminal with 3π / 4 and the reference angle is π / 4.
Explanation:
1) 19 π/4 = 4π + 3 π/4, which is 4 complete turns and 3/4 of turn.
2) 3 π/4 is in the third quadrant, so the reference angle is π - 3 π/4 = π/4
3) sin (π/4) = sin (3π/4) = (√2) / 2
4) csc (π/4) = 1 / [ sin (3π/4) ] = 1 / [ (√2) / 2 ] = 2 / (√2) = √2, which shows the validity of the statement and csc(19π/4) = √2.
Answer: (D) 2.394 * 10^-1
Step-by-step explanation:
(4.2 * 10^-1) (5.7 * 10^-1)
= 2.394 * 10^-1
Answer:

Step-by-step explanation:
We know that since angles in a triangle add up to 180º, the remaining angle must be 45º.
So the side with length
must be equal to the side with length
. That is:

Now, by Pythagoras:

Answer:
<D = 100
<E =30
<F =50
Step-by-step explanation
Given that triangles triangle ABC and triangle DEF are similar, this means that their angles are congruent i.e
<A = <D
<B = <E
<C = <F
Given
<A = 100 then <D = 100
<B = 30°, then <E = 30°
To get <F, we will use the expression
<D+<E+<F = 180 (sum of angles in a triangle is 180°)
100+30+<F = 180
130+<F = 180
<F = 180-130
<F = 50°
Hence the measure of <F is 50°