Answer:
5√3
Step-by-step explanation:
The ratio of side lengths in a 30-60-90 triangle is ...
1 : √3 : 2
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Multiplying by 5, we have ...
1 : √3 : 2 = x : y : 10 = 5 : 5√3 : 10
The value of y is 5√3.
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<em>Additional comment</em>
y is the side adjacent to the 30° angle, so can be found from ...
Cos = Adjacent/Hypotenuse
Adjacent = Cos × Hypotenuse . . . . . multiply by hypotenuse
y = cos(30°)×10 = (√3)/2 × 10 . . . . . . substitute corresponding values
y = 5√3
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The value of x is 5.
Answer:
Given: BD is an altitude of △ABC .
Prove: sinA/a=sinC/c
Triangle ABC with an altitude BD where D is on side AC. Side AC is also labeled as small b. Side AB is also labeled as small c. Side BC is also labeled as small a. Altitude BD is labeled as small h.
Statement Reason
BD is an altitude of △ABC .
Given △ABD and △CBD are right triangles. (Definition of right triangle)
sinA=h/c and sinC=h/a
Cross multiplying, we have
csinA=h and asinC=h
(If a=b and a=c, then b=c)
csinA=asinC
csinA/ac=asinC/ac (Division Property of Equality)
sinA/a=sinC/c
This rule is known as the Sine Rule.
Answer:
a) 24
b) 12
Step-by-step explanation:
a) For the 4 letters of the word ROCK
Selecting any first letter, we have 4 options
for the second, we have 3 options
for the third we have 2 options
for the fourth, we have only one option
So the number of ways will be ;
4 * 3 * 2 * 1 = 24 ways
b) 2 out of 4
For the first letter, we have 4 options, for the second, we have 3 options
so the number of options is 4 * 3 = 12 options