Math CentralQuandaries & Queries


Question from Carley, a student:

Hi my name is Carley. I am an 8th grader. What us the height of an equilateral triangle if the sides are 18 cm?

Hi Carley,

Draw a diagram.


D is the midpoint of BC and hence |CA| = 18 cm and |DC| = 9 cm. Angle ADC is a right angle. Do you see why? What does Pythagoras' theorem tell you about |AD|?


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