Using proportions, it is found that:
- Peter is walking at a rate of 3 km/h.
- MJ is biking at a rate of 9 km/h.
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- Peter is walking at a rate of x km/h.
- MJ is biking 6 km/h faster than Peter, thus 6 + x km/h.
- Opposite directions, thus, their distance increases at a rate of (6 + 2x) km each hour, as
.
6 + 2x km each hour, 18 km after 1.5 hours, thus, the rule of three is:
1h - (6 + 2x) km
1.5h - 18 km
Applying cross multiplication:






Then:
- Peter is walking at a rate of 3 km/h.
- MJ is biking at a rate of 9 km/h.
A similar problem is given at brainly.com/question/24112433
Answer: sqrt(2)/2 which is choice D
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Explanation
(3pi/4) radians converts to 135 degrees after multiplying by the conversion factor (180/pi).
The angle 135 degrees is in quadrant 2. We subtract the angle 135 from 180 to find the reference angle
180-135 = 45
Then you can use a 45-45-90 triangle to determine that the ratio of opposite over hypotenuse is sqrt(2)/2
sine is positive in quadrant 2
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Alternatively, you can use a unit circle. Refer to the diagram below. In red, I've circled the angle 3pi/4 radians. The terminal point for this angle has a y coordinate of sqrt(2)/2
Recall that y = sin(theta).
If 25% is 80, 100% is 320. 60% of 320 is 192.

<h3><u>Given </u><u>:</u><u>-</u></h3>
- We have given the coordinates of the triangle PQR that is P(-4,6) , Q(6,1) and R(2,9)
<h3><u>To</u><u> </u><u>Find </u><u>:</u><u>-</u></h3>
- <u>We </u><u>have </u><u>to </u><u>calculate </u><u>the </u><u>length </u><u>of </u><u>the </u><u>sides </u><u>of </u><u>given </u><u>triangle </u><u>and </u><u>also </u><u>we </u><u>have </u><u>to </u><u>determine </u><u>whether </u><u>it </u><u>is </u><u>right </u><u>angled </u><u>triangle </u><u>or </u><u>not </u>
<h3><u>Let's </u><u>Begin </u><u>:</u><u>-</u></h3>
<u>Here</u><u>, </u><u> </u><u>we </u><u>have </u>
- Coordinates of P =( x1 = -4 , y1 = 6)
- Coordinates of Q = ( x2 = 6 , y2 = 1 )
- Coordinates of R = ( x3 = 2 , y3 = 9 )
<u>By </u><u>using </u><u>distance </u><u>formula </u>

<u>Subsitute </u><u>the </u><u>required </u><u>values </u><u>in </u><u>the </u><u>above </u><u>formula </u><u>:</u><u>-</u>
Length of side PQ






Length of QR





Length of RP





<h3><u>Now</u><u>, </u></h3>
We have to determine whether the triangle PQR is right angled triangle
<h3>Therefore, </h3>
<u>By </u><u>using </u><u>Pythagoras </u><u>theorem </u><u>:</u><u>-</u>
- Pythagoras theorem states that the sum of squares of two sides that is sum of squares of 2 smaller sides of triangle is equal to the square of hypotenuse that is square of longest side of triangle
<u>That </u><u>is</u><u>, </u>

<u>Subsitute </u><u>the </u><u>required </u><u>values</u><u>,</u>


<u>From </u><u>above </u><u>we </u><u>can </u><u>conclude </u><u>that</u><u>, </u>
- The triangle PQR is not a right angled triangle because 205 ≠ 45 .
your calculations for volume (pi x r^2 × h) and surface area (2 × pi × r (h+r)) are correct. However your ratio are incorrect. From the formulas the ratio of surface area to volume would be r×h:2(h+r)