Difference between revisions of "1990 AHSME Problems/Problem 3"

(Created page with "== Problem == The consecutive angles of a trapezoid form an arithmetic sequence. If the smallest angle is <math>75^\circ</math>, then the largest angle is <math>\text{(A) } 95^...")
 
 
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== Solution ==
 
== Solution ==
<math>\fbox{D}</math>
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A trapezoid is a quadrilateral; therefore the interior angles sum to <math>360^\circ</math>.
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Thus <math>75+(75+x)+(75+2x)+(75+3x)=360</math>, so <math>x=10</math> and the largest angle is <math>105^\circ</math> which is <math>\fbox{C}</math>
  
 
== See also ==
 
== See also ==

Latest revision as of 02:44, 4 February 2016

Problem

The consecutive angles of a trapezoid form an arithmetic sequence. If the smallest angle is $75^\circ$, then the largest angle is

$\text{(A) } 95^\circ\quad \text{(B) } 100^\circ\quad \text{(C) } 105^\circ\quad \text{(D) } 110^\circ\quad \text{(E) } 115^\circ$

Solution

A trapezoid is a quadrilateral; therefore the interior angles sum to $360^\circ$. Thus $75+(75+x)+(75+2x)+(75+3x)=360$, so $x=10$ and the largest angle is $105^\circ$ which is $\fbox{C}$

See also

1990 AHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
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 26 27 28 29 30
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