A)
To be similar triangles have to have equal angles
triangle ZDB'
1)angle Z=90 degrees
triangle B'CQ
1) angle C 90 degrees
angle A'B'Q=90
DB'Z+A'B'Q+CB'Q=180, straight angle
DB'Z+90+CB'Q=180
DB'Z+CB'Q=90
triangle ZDB'
DZB'+DB'Z=180-90=90
DB'Z+CB'Q=90
DZB'+DB'Z=90
DB'Z+CB'Q=DZB'+DB'Z
2)CB'Q=DZB' (these angles from two triangles ZDB' and B'CQ )
3)so,angles DB'Z and B'QC are going to be equal because of sum of three angles in triangles =180 degrees and 2 angles already equal.
so this triangles are similar by tree angles
b)
B'C:B'D=3:4
B'D:DZ=3:2
CQ-?
DC=AB=21
DC=B'C+B'D (3+4= 7 parts)
21/7=3
B'C=3*3=9
B'D=3*4=12
B'D:DZ=3:2
12:DZ=3:2
DZ=12*2/3=8
B'D:DZ=CQ:B'C
3:2=CQ:9
CQ=3*9/2=27/2
c)
BC=BQ+QC=B'Q+QC
BQ' can be found by pythagorean theorem
The number=10x+y
we suggest this system of equations:
(10y+x)-(10x+y)=27
x+y=9 ⇒x=9-y
Can solve this system of equations by susbstitution method.
(10y+(9-y)-(10(9-y)+y)=27
10y+9-y-(90-10y+y)=27
10y-y+10y-y=27-9+90
18y=108
y=108/18
y=6
x=9-y
x=9-6
x=3
The number=10x+y=10(3)+6=36
Answer: the number is 36.
to check:
63-36=27
6+3=9
Answer:
1 round = 4 burpees 10 sit ups
Step-by-step explanation:
1 round = 4 burpees 10 sit ups
2 round = 8 burpees 20 sit ups
3 round = 12 burpees 30 sit ups
4 round = 16 burpees 40 sit ups
Answer:
B. 0.83
Step-by-step explanation:
I calculated it logically
Answer:
-33 or 33
Step-by-step explanation:
The seventh term of an AP is written as:
The eleventh term of an AP is written as:
If the 7th term is 11 times the 11th term, then;
Expand to get:
We must have a=-52 and d=5
Or
a=52 and d=-5
For the first case, the 18th term is :
For the second case,
