Answer:
CE = 17
Step-by-step explanation:
∵ m∠D = 90
∵ DK ⊥ CE
∴ m∠KDE = m∠KCD⇒Complement angles to angle CDK
In the two Δ KDE and KCD:
∵ m∠KDE = m∠KCD
∵ m∠DKE = m∠CKD
∵ DK is a common side
∴ Δ KDE is similar to ΔKCD
∴ 
∵ DE : CD = 5 : 3
∴ 
∴ KD = 5/3 KC
∵ KE = KC + 8
∵ 
∴ 
∴ 
∴ 
∴ 
∴ KC = (8 × 9) ÷ 16 = 4.5
∴ KE = 8 + 4.5 = 12.5
∴ CE = 12.5 + 4.5 = 17
Answer:
3) 16.2
Step-by-step explanation:
The supplement to the 115° angle on the right is 65°, the same as the angle at upper left. The vertical angles at C are the same measure, so this tells you that the two triangles FCB and ACD are similar by the AA similarity postulate. That being the case, corresponding sides are proportional:
CB/CD = CF/CA
CB = CD·CF/CA = 7.2·21.6/9.6
CB = 16.2
_____
When given two "point-to-point" triangles like this, quite often there is some sort of similarity relationship involved. First, you need to figure out what it is; then you need to make use of it as needed to answer the question being asked.
Cost of washer: $720
Cost of dryer: $240
I've taken this test before and got it right, so you're good :)
1 ) cot x * sin x = cos x
(cos x / sin x) * sin x = cos x
cos x = cos x
Answer: B ) cot x = cos x / sin x
2 ) ( sin² x + cos² x ) / cos x = sec x
1/cos x = sec x
sec x = sec x
Answer: C ) cos² x + sin² x = 1