Isosceles triangle has a base of length units. is the altitude to the base, and is the midpoint of side . The triangular area is three square units. Find the perimeter of triangle .
Source: NCTM Mathematics Teacher 2008
Let be the midpoint of . Triangle is an isosceles triangle and its area is one fourth the area of triangle because its area equals the area of triangle .
Area of times area of
Altitude in an isosceles triangle is also a perpendicular bisector.
by the Pythagorean theorem
Perimeter of triangle
Answer: length units