[solve each equation for the indicated variable] 2A=πr2 for π

Do anyone know the answer to this? Answers please?

Amanda [17]

Answer:

Yes

Step-by-step explanation:

You can check whether the ratios form a proportion, by setting one piece of the ratios as x

Thus, we can use the equation 4/3.2=22/x.

From this, we get 4x=70.4.

Solving for x gives us 17.6.

5 0

2 years ago

1. Find the value of x. A. 90 B. 80 C. 60 D. 45

tia_tia [17]

Answer:

A 90

Step-by-step explanation:

multiple ways to prove this.

e.g. since the angle between the two lines from the center of the circle to the 2 tangent touching points is 90 degrees (that is the meaning of these 90 degrees here as the angle of the circle segment defined by the 2 tangent touching points and the circle center), the tangents have the same "behavior" as tan and cot = the tangents at the norm circle at 0 and 90 degrees. they hit each other outside of the circle again at 90 degrees.

another way

imagine the two right triangles of the tangents crossing point to the circle center and the tangent/circle touching points.

the Hypotenuse of each triangle is cutting the 90 degree angle of the circle segment exactly in half (due to the symmetry principle). so the angle between radius side and Hypotenuse is 90/2 = 45 degrees.

that means also the angle of such a right triangle at the tangent crossing point is 45 degrees (as the sum of all angles in a triangle must be 180, we have the remainder of 180 - 90 - 45 = 45 degrees).

the angles of both right triangles at that point are the same, and so we can add 45+45 = 90 degrees for the total angle at the tangent crossing point.

8 0

3 years ago

Find the area of the regular trapezoid. The figure is not drawn to scale. The top side is 4, the bottom side is 7, and both side

svp [43]

A regular trapezoid is shown in the picture attached.

We know that:
DC = minor base = 4
AB = major base = 7
AD = BC = lateral sides or legs = 5

Since the two legs have the same length, the trapezoid is isosceles and we can calculate AH by the formula:

AH = (AB - DC) ÷ 2
= (7 - 5) ÷ 2
= 2 ÷ 2
= 1

Now, we can apply the Pythagorean theorem in order to calculate DH:
DH = √(AD² - AH²)
= √(5² - 1²)
= √(25 - 1)
= √24
= 2√6

Last, we have all the information needed in order to calculate the area by the formula:

$A = \frac{(AB + CD)DH}{2}$

A = (7 + 5) × 2√6 ÷ 2
= 12√6

The area of the regular trapezoid is 12√6 square units.

7 0

3 years ago

a person is standing on top of a smaller building looking across the street at a taller building, which is 260 feet away horizon

Anuta_ua [19.1K]

The height of the smaller building is 94.63 feet, computed using the trigonometric ratios.

In the question, we take AB to be the taller building, where A is its top and B is its base, CD to be the shorter building, where C is its top and D is its base, and CE to be the perpendicular from C to AB.

Given that the horizontal distance between the two buildings is 260 feet, we can say that BC = CE = 260 feet.

The angle of elevation from the top of the shorter building to the top of the taller building is 30°, that is, ∠ECA = 30°.

The angle of depression from the top of the shorter building to the base of the taller building is 20°, that is, ∠ECB = 20°.

When ∠ECB = 20°, then ∠CBD = 20°, as they are alternate angles.

We are asked to find the height of the shorter building, that is, we are asked to find CD.

In ΔCBD,

tan ∠CBD = CD/BD {perpendicular/base},

or, tan 20° = CD/260,

or, CD = 260*tan 20° = 260*0.36397023426 {∵ tan 20° = 0.36397023426},

or, CD = 94.6322609092.

Therefore, the height of the smaller building is 94.63 feet, computed using the trigonometric ratios.

Learn more about heights and distances at

brainly.com/question/2004882

#SPJ4

7 0

2 years ago

Find the x and y intercepts of the graph of the equation y=x^2-5

mr_godi [17]

Answer:

x intercepts -sqrt(5), + sqrt(5)

y intercept -5

Step-by-step explanation:

y = x^2 -5

to find the x intercept set y=0 and solve for x

0 = x^2-5

add 5 to each side

5 = x^2

take the square root of each side

+- sqrt(5) = sqrt(x^2)

x = +-sqrt(5) there are 2 x intercepts since it is a quadratic

to find the y intercept set x=0 and solve for y

y = 0-5

y = -5

8 0

3 years ago