What number should be added two -77 to get a sum of 36

The perimeter of equilateral triangle ABC is 81/3 centimeters, find the length of the radius and apothem.

MAXImum [283]

There is a typo error, the perimeter of equilateral triangle ABC is 81/√3 centimeters.

Answer:

Radius = OB= 27 cm

Apothem = 13.5 cm

A diagram is attached for reference.

Step-by-step explanation:

Given,

The perimeter of equilateral triangle ABC is 81/√3 centimeters.

Substituting this in the formula of perimeter of equilateral triangle = $3\times\ side$

$3\times\ side$ $=[tex]81\sqrt{3}$

$Side = \frac{81\sqrt{3} }{3} =27\sqrt{3} \ cm$

Thus from the diagram , Side $AB=BC=AC= 27\sqrt{3} \ cm$

We know each angle of an equilateral triangle is 60°.

From the diagram, OB is an angle bisector.

Thus $\angle OBC = 30$ °

Apothem is the line segment from the mid point of any side to the center the equilateral triangle.

Therefore considering ΔOBE, and applying tan function.

$tan\theta =\frac{perpendicular}{base} \\tan\theta=\frac{OE}{BE} \\tan\theta=\frac{OE}{\frac{27\sqrt{3}}{2} } \\tan30\times {\frac{27\sqrt{3} }{2} }= OE\\\frac{1}{\sqrt{3} } \times\frac{27\sqrt{3} }{2} =OE\\$

Thus ,apothem OE= 13.5 cm

Now for radius,

We consider ΔOBE

$cos\theta=\frac{base}{hypotenuse} \\cos30= \frac{BE}{OB} \\Cos30 = \frac{\frac{27\sqrt{3} }{2}}{OB} \\OB= \frac{\frac{27\sqrt{3} }{2}}{cos30} \\OB= \frac{\frac{27\sqrt{3} }{2}}{\frac{\sqrt{3} }{2} } \\OB =27 \ cm$

Thus for

Perimeter of equilateral triangle ABC is 81/√3 centimeters,

The radius of equilateral triangle ABC is 27 cm

The apothem of equilateral triangle ABC is 13.5 cm

4 0

3 years ago

Some one help not sure! i’ll mark brainlest

Anna [14]

Answer:

Ya, Its B.

Step-by-step explanation:

You divide the centimeter value you buy a 100 to get the meter value

5 0

3 years ago

Read 2 more answers

Midpoint of (-3,2) (3,2)

Leno4ka [110]

Answer: (0, 2)

Step-by-step explanation:

Do (x1+x2/2, y1+y2/2) as your formula to find the midpoints. -3+3/2=0 and 2+2/2=2 so the midpoint is (0, 2). Hope this helps, have a blessed and wonderful day as well as a safe one and stay healthy!

3 0

3 years ago

733 times 60 and work it out on your asnwcer plzz

grin007 [14]

Answer:

733 x 60 = 43,980.

Step-by-step explanation:

Another way to do this equation is by adding 733 by itself 60 times.

5 0

3 years ago

Find the perimeter and the area of each shape. Give your answer as a completely simplified exact value in terms of π (no approxi

nydimaria [60]

Answer:

Circumference: 12π + 8 cm,

Area: 48 ( cm )^2

Step-by-step explanation:

This figure is composed of circles, squares, and semicircles. As you can see, the squares indicate that each semicircle should have ( 1 ) the same area, and ( 2 ) the same length ( circumference ). It would be easier to take the circumference of the figure first, as it is composed of arcs part of semicircles the same length.

Circumference of 1 semicircle = $\frac{1}{2}$ ( πd ) = $\frac{1}{2}$ π( 4 ) = 2π ( cm )

Circumference of Figure (composed of 6 semicircles + 2 sides of a square),

We know that 6 semicircles should be 6 $*$ 2π, and as the sides of a square are equal - if one side is 4 cm, the other 3 are 4 cm as well. Therefore the " 2 sides of a square " should be 2

Circumference of Figure = 6 $*$ 2π + 2 = 12π + 8 ( cm )

_____________

The area of this figure is our next target. As you can see, it is composed of 3 semicircles, and the area of 3 semicircles subtracted from the area of 3 squares. Therefore, let us calculate the area of 1 semicircle, and the area of 1 square first.

Area of 1 semicircle = 1/2π $r^2$ = 1/2π $(2)^2$ = 2π ( cm ),

Area of 1 square = ( 4 cm )( 4 cm ) = 16 ( $cm^2$ )

So, the area of the figure should be the following -

Area of Figure = 3 $*$ 2π + 3( 16 - 2π ) = 48 ( cm )^2

3 0

2 years ago