Difference between revisions of "2016 AMC 12B Problems/Problem 4"

(Solution)
Line 6: Line 6:
  
 
==Solution==
 
==Solution==
 +
We can set up equations to find each angle. The larger angle will be represented as <math>x</math> and the larger angle will we represented as <math>y</math>. We can get the equations
 +
 +
<math>4x=5y</math>
 +
 +
and
 +
 +
<math>2\times(90-x)=90-y</math>
 +
 +
since the larger the original angle, the smaller the complement.
 +
We then find that <math>x=75</math> and <math>y=60</math>, there sum is <math>\boxed{\textbf{(C)}\ 135}</math>
  
 
==See Also==
 
==See Also==
 
{{AMC12 box|year=2016|ab=B|num-b=3|num-a=5}}
 
{{AMC12 box|year=2016|ab=B|num-b=3|num-a=5}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 11:27, 21 February 2016

Problem

The ratio of the measures of two acute angles is $5:4$, and the complement of one of these two angles is twice as large as the complement of the other. What is the sum of the degree measures of the two angles?

$\textbf{(A)}\ 75\qquad\textbf{(B)}\ 90\qquad\textbf{(C)}\ 135\qquad\textbf{(D)}\ 150\qquad\textbf{(E)}\ 270$

Solution

We can set up equations to find each angle. The larger angle will be represented as $x$ and the larger angle will we represented as $y$. We can get the equations

$4x=5y$

and

$2\times(90-x)=90-y$

since the larger the original angle, the smaller the complement. We then find that $x=75$ and $y=60$, there sum is $\boxed{\textbf{(C)}\ 135}$

See Also

2016 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 3
Followed by
Problem 5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png