What method can you use to find the product of 70×55

This problem is only for smart kids, all people who dont do it r babies

Phantasy [73]

Answer:

46

Step-by-step explanation:

∠DAC ≅ ∠ACB because they are opposite interior angles where transversal AC crosses parallel lines BC and AD.

∠DAC ≅ ∠CAB because they are corresponding angles of the similar triangles ΔABC and ΔACD.

Hence ∠ACB ≅ ∠CAB and ΔABC is isosceles with side lengths both being 9. The corresponding side lengths of ΔACD are 12, meaning the base of ΔABC, segment AC, is 12. The scale factor of ΔACD to ΔABC is then 12:9 = 4:3, so the base AD of ΔACD is (4/3)×12 = 16.

So, the side lengths of the trapezoid are ...

AB = 9
BC = 9
CD = 12
DA = 16

and the perimeter is 9 +9 +12 +16 = 46 units.

3 0

3 years ago

A 10-foot ladder is leaning against a vertical wall. If the bottom of the ladder is being pulled away from the wall at the rate

Alex777 [14]

Answer:

The area is changing at 15.75 square feet per second.

Step-by-step explanation:

The triangle between the wall, the ground, and the ladder has the following dimensions:

H: is the length of the ladder (hypotenuse) = 10 ft

B: is the distance between the wall and the ladder (base) = 6 ft

L: the length of the wall (height of the triangle) =?

dB/dt = is the variation of the base of the triangle = 9 ft/s

First, we need to find the other side of the triangle:

$H^{2} = B^{2} + L^{2}$

$L = \sqrt{H^{2} - B^{2}} = \sqrt{(10)^{2} - B^{2}} = \sqrt{100 - B^{2}}$

Now, the area (A) of the triangle is:

$A = \frac{BL}{2}$

Hence, the rate of change of the area is given by:

$\frac{dA}{dt} = \frac{1}{2}[L*\frac{dB}{dt} + B\frac{dL}{dt}]$

$\frac{dA}{dt} = \frac{1}{2}[\sqrt{100 - B^{2}}*\frac{dB}{dt} + B\frac{d(\sqrt{100 - B^{2}})}{dt}]$

$\frac{dA}{dt} = \frac{1}{2}[\sqrt{100 - B^{2}}*\frac{dB}{dt} - \frac{B^{2}}{(\sqrt{100 - B^{2}})}*\frac{dB}{dt}]$

$\frac{dA}{dt} = \frac{1}{2}[\sqrt{100 - 6^{2}}*9 - \frac{6^{2}}{\sqrt{100 - 6^{2}}}*9]$

$\frac{dA}{dt} = 15.75 ft^{2}/s$

Therefore, the area is changing at 15.75 square feet per second.

I hope it helps you!

5 0

3 years ago

on a map with a scale 1: 25000,the area of a lake is 33.6 square centimeters. calculate the actual area of the lake, giving your

svlad2 [7]

Given :

On a map with a scale 1: 25000 .

The area of a lake is 33.6 square centimeters.

To Find :

The actual area of the lake.

Solution :

Let, actual area of lake is A.

So,

$\dfrac{33.6}{A}=\dfrac{1}{25000}\\\\A = 840000\ cm^2$

We know , $1 \ cm^2 = 10^{-10}\ km^2$

Area in km² is :

$A = 840000\times 10^{-10}\ km^2\\\\A = 8.4 \times 10^{-5}\ km^2$

Hence, this is the required solution.

6 0

2 years ago

I need help u don’t know the answer please don’t make me get it wrong

Paul [167]

Answer:

16cm

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

An old cell phone battery would last for 16 hours. The new battery lasts 25% longer. How long will the new battery last?

Aliun [14]

Answer:

20 hours

Step-by-step explanation:

To find the answer, you first should find out how long is 25% of the original battery life, 16 hours. To find this, you can divide 16 by 4, or multiply 16 by 0.25. Either works.

16/4=4.

So the new battery lasts 4 hours more than the old battery. Then, add this to the original length to find how long the new battery will last in total.

16+4=20

7 0

3 years ago