All categories

3 years ago

Describe and correct the error in finding DC

Mathematics

1 answer:

sleet_krkn [62]3 years ago

6 0

Answer:

DC = 2

Step-by-step explanation:

The wrong equation was used.

The right equation to use based on the midsegment theorem of a trapezoid is:

MN = ½(AB + DC)

MN = 8

AB = 14

Substitute

8 = ½(14 + DC)

Multiply both sides by 2

8*2 = ½(14 + DC)*2

2*8 = 14 + DC

16 = 14 + DC

16 - 14 = 14 + DC - 14

2 = DC

DC = 2

You might be interested in

Triangle ABC has a right angle at angle c and pounts e,d and f are midpoints. Line df = 3 and line segment ab= 10. What is the l

Leni [432]

See the attached figure.
========================
AB = 10 , FD = 3
∵ D is the midpoint of AB, and F is the mid point of CB
∴ FD // AC , FD = 0.5 AC
∵ Δ ABC is a right triangle at C
∴ FD ⊥ BC
∴ BD = 0.5 AB = 5
∴ in Δ FDB ⇒⇒ BF² = BD² - FD² = 5² - 3² = 16
∴ BF = √16 = 4
∵ F is the mid point of CB
∴ CF = BF = 4 , and CB = 2 BF = 2*4 = 8
∵ D is the midpoint of AB, and E is the mid point of AC
∴ DE // CB , and DE = 0.5 CB = 0.5 * 8 = 4

∴ T<span>he length of line ED is 4
</span>

8 0

3 years ago

Please ..........help me

Ad libitum [116K]

Answer:

First statement: 10 road workers take 5 days to complete a work, working 2 hours a day.

Let us calculate how many days 2 workers will need, if they were to work at the same pace (i.e. each working 2 hours a day). The workforce is now decreased to 2 divided by 10 = 1/5 (i.e. one-fifth).

Therefore proportionately, the time will increase to 5 days divided by 1/5, (i.e. 5 / (1/5) = 25 days.

We now know that 2 workers will need 25 days to finish the work, if they work for 2 hors a day.

Now the question is what will happen if the two people work 5 hours per day, instead of 2 hours per day?

The labor they put in has increased to 5 divided by 2 = 2.5 (i.e. 2 and half times).

Consequently, the time needed to finish the work will decrease to 25 divided by 2.5 (i.e. ( 25 / 2.5 ) = 10. days.

The answer : 10 Days.

6 0

3 years ago

Find X (Show Your Work)<br> WILL MARK BRAINLIEST!

Rudiy27

Answer:

its 8 cause 2 times x is 40 40+-40= 0 so 2 times 4 is 8

Step-by-step explanation:

6 0

3 years ago

I NEED HELP ASAP!!!!!!!!!!

svetoff [14.1K]

Answer:

I know the answer

Step-by-step explanation:

x = random number then y = x + y then x = 68 So we can conclude

5 0

2 years ago

A post is supported by two wires (one on each side going in oppositedirections) creating an angle of 80° between the wires. The

Vladimir [108]

Using the Sine rule,

$\frac{\sin A}{A}=\frac{\sin B}{B}=\frac{\sin C}{C}$ $\begin{gathered} \text{Let A = 14m,} \\ Substituting the variables into the formula,Where the length of the wires are, AP = xm and BP = ym[tex]\begin{gathered} \frac{\sin80^0}{14}=\frac{\sin40^0}{x} \\ \text{Crossmultiply,} \\ x\times\sin 80^0=14\times\sin 40^0 \\ Divide\text{ both sides by }\sin 80^0 \\ x=\frac{14\sin40^0}{\sin80^0} \\ x=9.14m \end{gathered}$

Hence, the length of wire AP (x) is 9.14m.

For wire BP (y)m,

Sum of angles in a triangle is 180 degrees,

$A^0+P^0+B^0=180^0$ $\begin{gathered} \text{Where A}^0=\text{ unknown,} \\ P^0=80^0\text{ and,} \\ B^0=40^0 \\ A^0+80^0+40^0=180^0 \\ A^0+120^0=180^0 \\ A^0=180^0-120^0 \\ A^0=60^0 \end{gathered}$

Using the side rule to find the length of wire BP,

$\begin{gathered} \frac{\sin 60^0}{y}=\frac{\sin 80^0}{14} \\ \text{Crossmultiply,} \\ y\times\sin 80^0=14\times\sin 60^0 \\ \text{Didive both sides by }\sin 80^0 \\ y=\frac{14\times\sin 60^0}{\sin 80^0} \\ y=12.31m \end{gathered}$

Hence, the length of wire BP (y) is 12.31m

Therefore, the length of the wires are (9.14m and 12.31m).

4 0

1 year ago