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3 years ago

Answer with explanation will mark brainliest for best response

Mathematics

2 answers:

Elina [12.6K]3 years ago

7 0

Answer:

Angle B = 106.6 degrees

Step-by-step explanation:

b^2= a^2+c^2-2*a*c*cosB

9*9 = 4*4 + 7*7 - 2*7*4*cosB

81= 16+49-56cosB Subtract 16 and 49 from both sides

16= -56cosB Divide by -56 on both sides.

cosB= -16/56 Take the arccosine of both sides

B=arccos(-16/56)

B= 106.6

Zolol [24]3 years ago

4 0

Answer:

B. 106.6

Step-by-step explanation:

To solve for angle B, we can use the law of cosines.

Recall that the law of cosines states $b^2=a^2+c^2-2ab*cos(B)$

When this is solved for angle B, we get $B=cos^{-1}( \frac{a^2+c^2-b^2}{2ac} )$

In this triangle, $a=7, b=9, c=4$

Now, we can plug these numbers into our equation and then simplify to get B.

$B=cos^{-1}( \frac{7^2+4^2-9^2}{2(7)(4)} )\\\\B=cos^{-1}( \frac{49+16-81}{56} )\\\\B=cos^{-1} (\frac{-16}{56} )\\\\B=106.602\\\\B=106.6$

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We have seen that isosceles triangles have two sides of equal length. The angles opposite these sides have the same measure. Use

Naddik [55]

Question has missing figure, the figure is in the attachment.

Answer:

The measure of ∠1 is 65°.

The measure of ∠2 is 65°.

The measure of ∠3 is 50°.

The measure of ∠4 is 115°.

The measure of ∠5 is 65°.

Step-by-step explanation:

Given,

We have an isosceles triangle which we can named it as ΔABC.

In which Length of AB is equal to length of BC.

And also m∠B is equal to m∠C.

ext.m∠C= 115°(Here ext. stands for exterior)

We have to find the measure of angles angles 1 through 5.

Solution,

For ∠1.

∠1 and ext.∠C makes straight angle, and we know that the measure of straight angle is 180°.

So, we can frame this in equation form as;

$\angle1+ext.\angle C=180\°$

On putting the values, we get;

$\angle 1+115\°=180\°\\\\\angle1=180\[tex]\therefore m\angle2=65\°$ -115\°=65\°[/tex]

Thus the measure of ∠1 is 65°.

For ∠2.

Since the given triangle is an isosceles triangle.

So, $m\angle1=m\angle2$

Thus the measure of ∠2 is 65°.

For ∠3.

Here ∠1, ∠2 and ∠3 are the three angles of the triangle.

So we use the angle sum property of triangle, which states that;

"The sum of all the angles of a triangle is equal to 180°".

$\therefore \angle1+\angle2+\angle3=180\°$

Now we put the values and get;

$65\°+65\°+\angle3=180\°\\\\130\°+\angle3=180\°\\\\\angle3=180\°-130\°=50\°$

Thus the measure of ∠3 is 50°.

For ∠4.

∠4 and ∠2 makes straight angle, and we know that the measure of straight angle is 180°.

So, we can frame this in equation form as;

$\angle2 +\angle 4 =180\°$

Substituting the values of of angle 2 to find angle 4 we get;

$65\°+ \angle 4 = 180\°\\\\ \angle 4 = 180\°-65\°\\\\\angle 4= 115\°$

Thus the measure of ∠4 is 115°.

For ∠5.

∠4 and ∠5 makes straight angle, and we know that the measure of straight angle is 180°.

So, we can frame this in equation form as;

$\angle4 +\angle 5 =180\°$

Substituting the values of of angle 4 to find angle 5 we get;

$115\°+ \angle 5 = 180\°\\\\ \angle 5 = 180\°-115\°\\\\\angle 5= 65\°$

Thus the measure of ∠5 is 65°.

Hence:

The measure of ∠1 is 65°.

The measure of ∠2 is 65°.

The measure of ∠3 is 50°.

The measure of ∠4 is 115°.

The measure of ∠5 is 65°.

6 0

3 years ago

Find the value of 3mm(m+y)

malfutka [58]

Answer:

Step-by-step explanation:

3mn (m+y)

= 3 $m^{2}$ n + 3mny

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3 years ago

24 students in a class took an algebra test.

Vlada [557]

Answer:

75 % passed

25 % did NOT pass

Step-by-step explanation:

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2 years ago

Read 2 more answers

What is a necessary step for constructing perpendicular lines through a point off the line?

Nostrana [21]

Answer:

Find another point on the perpendicular line.

Step-by-step explanation:

Given an original line "m", and a point off the line "Q", in order to construct a second line "p", meant to be perpendicular to "m" through the point "Q", fundamentally, the only truly necessary step to construct a perpendicular line through is to find another point on the yet-to-be-found perpendicular line.

Most often, this is accomplished by exploiting the fact that "p" is the set of all points that are equidistant from any pair of points that are symmetric about "p".

Since the symmetry must be about "p", and we don't even know where "p" is, one often finds two points on "m" that are equidistant from "Q".

This can be accomplished by adjusting a compass to a fixed radius (larger than the distance from "Q" to "m"), and making an arc that intersects "m" in two places. Those two places will be equidistant from "Q", and are simultaneously on line "m". Thus, these two points, "A" & "B" are symmetric about "p".

Since "A" & "B" are symmetric about "p", they are equidistant from "p", and are on "m". One could try to find the point of intersection between "p" and "m" through construction, but this is unnecessary. We need only find a second point (besides "Q") that is equidistant from "A" & "B", which will necessarily be a point on "p", to form the line perpendicular to "m".

To do this, fix the compass with any radius, and from "A" make a large arc generally in the direction of "B", and make the same radius arc from "B" in the direction of "A" such that the two arcs intersect at some point that isn't "Q". This point of intersection we can call point "T", and the line QT is line "p", the line perpendicular to the original line, necessarily containing "Q".

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2 years ago

College bookstore charge $60 for a yearly membership. Books will then only cost $7.60 each, tax included. Right in equation to r

Yuri [45]

Equation - 7.60b+60=m

7.60b+60=100
You’d be able to buy 5 books

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3 years ago