All categories

2 years ago

Heeeeeeeeelppp ppppppppppppppppppppppppplllllassss

Mathematics

1 answer:

SVETLANKA909090 [29]2 years ago

8 0

Answer:

AC= 20

Step-by-step explanation:

since the two figures are similar, CB Is congruent to FD

since image/preimage, 12/3 =4

The dilation is 4.

AC is congruent to EF

EF=5

4 x 5 = 20

AC=20

someone correct me if im wrong :)

You might be interested in

8-35. Use your knowledge of polygons to answer the questions below, if possible.

Nataliya [291]

Answer:

(a)I. 13 Sides II. 7 Sides

(b) 4 Sides, Square

(c)x=52 degrees

(d)x=107 degrees

(e)1620 degrees

Step-by-step explanation:

(a)The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

I. If the Interior angle is $1980^0$

Then:

$(n-2)180^0=1980^0\\$Divide both sides by 180^0 $ to isolate n$\\n-2=11\\$Add 2 to both sides of the equation\\n-2+2=11+2\\n=13$

The polygon has <u>13 sides.</u>

II. If the Interior angle is $900^0$

Then:

$(n-2)180^0=900^0\\$Divide both sides by 180^0 $ to isolate n$\\n-2=5\\$Add 2 to both sides of the equation\\n-2+2=5+2\\n=7$

The polygon has <u>7 sides.</u>

(b)The sum of the exterior angle of a polygon is 360 degrees,

Each exterior angle of a n-sided regular polygon is: $\frac{360^0}{n}$

If the exterior angle of a regular polygon is 90°

Then:

$90\°=\frac{360^0}{n}\\ 90n=360\\n=4$

The regular polygon has 4 sides and it is called a <u>Square.</u>

<u>(c)</u>The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

Each Interior angle of a regular n-sided polygon is: $\frac{(n-2)180^0}{n}$

For a pentagon, n=5

Then:

$\frac{(5-2)180^0}{5}=2x+4\\108=2x+4\\108-4=2x\\104=2x\\x=52^0$

(d)The <u>sum of the exterior angle of a polygon is 360 degrees.</u>

If four of the exterior angles of a pentagon are 57, 74, 56, and 66.

Let the fifth angle=x

Then:

$57+74+56+66+x=360^0\\253+x=360\\x=107^0$

(e)The Sum of the Interior angle of polygon with n sides is derived using the formula: (n-2)180.

In an 11-gon., n=11

Therefore, the sum of the interior angle=(11-2)180= $1620^0$

The sum of the interior angle <u>does not change either in a regular or irregular polygon.</u>

3 0

3 years ago

Mrs. Smith's class is working on a variety of science experiments. Each

SVETLANKA909090 [29]

Answer:

Step-by-step explanation:

If there are <em>n</em> students, then the number of pairs is $\frac{n(n-1)}{2}$ .

With 12 students, $\frac{12(12-1)}{2} = \frac{132}{2}=66$ pairs can be formed.

The reason the formula works is this: Each of the 12 students can be paired with 11 other students (no student is paired with him/her self). But counting 12 x 11 = 132 counts each pair <u>twice</u>. Example: student A can be paired with student B,..., student B can be paired with student A. The pair was counted two times.

See the attached image that shows pairings of 5 students. There are

5(5 - 1)/2 = 5(4)/2 = 10 pairs.