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3 years ago

What is the area of triangle DEF

Mathematics

1 answer:

kolezko [41]3 years ago

3 0

Answer:

76.5 cm²

Step-by-step explanation:

Given the triangles are similar , then

ratio of sides = a : b , so

ratio of areas = a² : b²

Here ratio of sides = 9 : 13.5 = 2 : 3

ratio of areas = 2² : 3² = 4 : 9

let x be the area of Δ DEF and using proportion

$\frac{4}{34}$ = $\frac{9}{x}$ ( cross- multiply )

4x = 306 ( divide both sides by 4 )

x = 76.5

The area of Δ DEF = 76.5 cm²

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5. During the election for class president,

Alex Ar [27]

60 more students voted for Kevin

Step-by-step explanation:

Given

total students = 300

Voted for Jennifer = 40%

Voted for Kevin = 60%

We will find number of students for one of them and then will subtract from total to find the others.

So,

Students who voted for Jennifer:

$= 40\%\ of\ 300\\=0.40*300\\=120\ students$

Students who voted for Kevin

= $=Total\ students-Students\ who\ voted\ for\ Jennifer\\=300-120\\=180\ students$

In order to calculate that how many more students voted for Kevin :

180-120 = 60

Hence,

60 more students voted for Kevin

Keywords: Percentage

Learn more about percentage at:

#LearnwithBrainly

4 0

3 years ago

Tomas wants to buy a new baseball bat. The one he likes costs $130, but it's one sale for $104. What is the percent of the disco

OLga [1]

130 x .20% = 26
130-26 = 104
So 20%

3 0

2 years ago

Read 2 more answers

Lamar is writing a coordinate proof to show that a segment from the midpoint of the hypotenuse of a right triangle to the opposi

Zanzabum

1. N is a midpoint of the segment KL, then N has coordinates

$\left(\dfrac{x_K+x_L}{2},\dfrac{y_K+y_L}{2} \right) =\left(\dfrac{0+2a}{2},\dfrac{2b+0}{2} \right) =(a,b).$

2. To find the area of △KNM, the length of the base MK is 2b, and the length of the height is a. So an expression for the area of △KNM is

$A_{KMN}=\dfrac{1}{2}\cdot \text{base}\cdot \text{height}=\dfrac{1}{2}\cdot 2b\cdot a=ab.$

3. To find the area of △MNL, the length of the base ML is 2a and the length of the height is b. So an expression for the area of △MNL is

$A_{MNL}=\dfrac{1}{2}\cdot \text{base}\cdot \text{height}=\dfrac{1}{2}\cdot 2a\cdot b=ab.$

4. Comparing the expressions for the areas you have that the area $A_{KMN}$ is equal to the area $A_{MNL}$ . This means that the segment from the midpoint of the hypotenuse of a right triangle to the opposite vertex forms two triangles with equal areas.