1) The triangles are congruent by SSS.
The two tick marks indicate two pairs of congruent sides; it is evident that the third side is congruent by the way the diagram is drawn - the bases of the triangles are together and appear to be the same length.
2) The triangles are congruent by SAS.
The two pairs of tick marks indicate congruent sides, and their included angles are congruent because they are vertical angles, and vertical angles are always congruent.
First compute the mean:
(4.67 + 4.98 + 4.34) / 3 = 4.66
then compute the variance:
(4.67-4.66)^2 = 0.0001
(4.98-4.66)^2 = 0.1024
(4.34-4.66)^2 = 0.1024
sum of the three = 0.2049
then take the square root:
= 0.452
the standard deviation is 0.452
Doming ran a total of 4 miles not 4.75. This is because if we take away the 6 minutes of walking, it will be 32 minutes left of just running, and if he is going exactly 8 minutes per mile then he ran 4 miles in total.
Answer:
Let's denote:
x: number of bicycles
y: number of skateboards
Then, we have:
x + y = 20
2x + 4y = 52
=> 2(20 - y) + 4y = 52
=> 2y = 12
=> y = 6 (number of skateboards)
=> x = 14(number of bicycles)
Hope this helps!
:)