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Help me !!

Angles α and β are the two acute angles in a right triangle, where
α = 5x/3 + 20 and β = 2x/3+ 14. Find α.
A) 24°
B) 30°
C) 60°
D) 66°

User RotaJota
by
6.9k points

1 Answer

2 votes
Short Answer C
Nice little problem. The catch is that alpha and beta both add up to 90 degrees.
Here's why.

α + β + right angle = 180° All triangles have 180° A right and = 90°.
α + β + 90 = 180 Right angles are 90° Now subtract 90° from both sides
α + β = 180 - 90
α + β = 90

Now all you have to do is put in the x values for alpha and beta and equate them to 90

5x/3 + 20 + 2x/3 + 14 = 90 Collect the light terms.
5x/3 + 2x/3 + 20 + 14 = 90
7x/3 + 34 = 90 Subtract 24 from both sides.
7x/3 = 90 - 34
7x/3 = 56 Multiply by sides by 3
7x = 3*56
7x = 168 Divide by 7
x = 168/7
x = 24

That's not quite the answer
The question wants alpha.
α = 5x / 3 + 20
α = 5*24/3 + 20
α = 120/3 + 20
α = 40 + 20
α = 60

Answer C <<<<<<



User Shreyansh Panchal
by
6.1k points