A right triangle has legs of \(5\,\text{cm}\) and \(12\,\text{cm}\). Its hypotenuse is \(13\,\text{cm}\).
a) Explain why each leg can serve as the height corresponding to the other leg. Give both of these heights.
b) Find the area of the triangle.
c) Find the height drawn to the hypotenuse. Round to the nearest hundredth.
Hints
- What does the right angle tell you about the two legs and their corresponding heights?
- Use the area you found to write a second area equation with the hypotenuse as the base.
- Rearrange the triangle area formula to solve for a height.
Solution
1. The legs are perpendicular. Therefore, the height corresponding to the \(5\,\text{cm}\) leg is \(12\,\text{cm}\), and the height corresponding to the \(12\,\text{cm}\) leg is \(5\,\text{cm}\).
2. The area is \(A=\frac{1}{2}\times5\times12=30\,\text{cm}^2\).
3. Let \(h\) be the height drawn to the hypotenuse. Using the hypotenuse as the base, \(30=\frac{1}{2}\times13\times h\). Thus, \(h=\frac{60}{13}\,\text{cm}\approx4.62\,\text{cm}\).
Answer
a) The two heights are \(12\,\text{cm}\) and \(5\,\text{cm}\), respectively.
b) \(30\,\text{cm}^2\)
c) \(\approx4.62\,\text{cm}\)