What is the area of a triangle whose sides are 5,5, and 6?
A) 6
B) 12
C) 16
D) 18
E) 24

Here’s that triangle:

5-5-6 1

You know you need a triangle’s height to calculate its area, and you know (or if you didn’t, you do now) that when you draw a vertical like that in an isosceles triangle, you make a perpendicular bisector to the base.

If you know your Pythagorean Triples well enough, you’re already done. You should always be on the lookout for 3-4-5 triangles on the SAT. 5-5-6 2The height of the triangle is 4, and its base is 6. The area, then, is \dfrac{1}{2}(6)(4)=12.


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