Answer:
0.51 cm
Step-by-step explanation:
In right triangle MNP, MP = 4 cm, m∠N = 90°, m∠P = 21°
By the sine definition,

Now, consider right triangle HMN (it is right because NH is an altitude). By the cosine definition,

In the right triangle, two acute angles are always complementary, so

Thus,

Answer:
Most known one: 4 sides
Step-by-step explanation:
They are closed shapes, their sides should be straight, they are strictly 2 dimensional, and finally, all quadrilaterals have 4 sides.
The answer is C because it is at the first of four intervals between 0 and 1
Answer:
infinitely many
Step-by-step explanation:
12x + 1 = 3(4x + 1) - 2
Distribute
12x + 1 = 12x + 3 - 2
Combine like terms
12x+1 = 12x +1
Subtract 12x from each side
1 =1
Since this is always true, we have infinite solutions
Answer:
x = -3 or x = 3
Step-by-step explanation:
Subtract 9 from both sides.
x^2 - 9 = 0
Factor the left side. There is no common factor of the terms. It is a binomial which is the difference of two squares, so it factors into the product of a sum and a difference.
(x + 3)(x - 3) = 0
Set each factor equal to zero.
x + 3 = 0 or x - 3 = 0
Solve each equation.
x = -3 or x = 3