With the whole question ???
Answer:
Perimeter=42cm
Step-by-step explanation:
It is given that AC is the angle bisector of the trapezoid ABCD which divides the trapezoid into two similar triangles that are △ABC and △ACD.
Now, it is also given that AB=9cm and CD=12cm.
Since, it is a trapezoid, then AB will be parallel to CD, thus
∠BAC=∠DCA (Alternate angles)
Also, it is given that ∠DAC=∠BAC
⇒∠DAC=∠DCA
Also, ∠ACD=∠ACB( Angle bisector)
Therefore, If the angles are equal, then the corresponding sides will also be equal. Hence, △ABC and △ACD are isosceles triangle, therefore
AB=BC=9cm and CD=AD=12cm
Now, the perimeter of trapezoid is the sum of all the four sides of the trapezoid, therefore
Perimeter=AB+AD+CD+BC
Perimeter=9+9+12+12
Perimeter=42cm
Answer:
B and C
Step-by-step explanation:
A. y + 11 = 22 → subtract 11 from both sides:
y = 11
---------------------------------------------------------------------------
B. 8 = 18 - y → subtract 18 from both sides:
-10 = -y → divide both sides by -1:
10 = y
----------------------------------------------------------------------------
C. 60 = 6y → divide both sides by 6:
10 = y
-----------------------------------------------------------------------------
D. = 4 → multiply both sides by 5:
y = 20
-----------------------------------------------------------------------------
E. 10y = 20 → divide both sides by 10:
y = 2
Answer:
Step-by-step explanation:
2½ hours × 640 miles/hour = 2½×640 miles = 1,600 miles