Pearson Algebra 1 Common Core, 2011
PA
Pearson Algebra 1 Common Core, 2011 View details
1. The Pythagorean Theorem
Continue to next subchapter

Exercise 39 Page 618

Yes, see solution.

Practice makes perfect

If two forces A and B pull at right angles to each other, the resultant force C can be represented by the diagonal of a rectangle. The diagonal is the hypotenuse of a right triangle. Since the opposite sides of a rectangle are equal lengths, both right triangles have the same base and height measurements, and a shared hypotenuse.

Forces Pulling at Right Angles
Let's consider one of the right triangles, and express the relation between the forces A, B, and C using the Pythagorean Theorem.

a^2+b^2=c^2 ⇔ A^2+B^2=C^2 We want to know if the given forces, 50 pounds and 120 pounds, will be pulled at right angles if their resultant force is 130 pounds. In order to check this, we will use the Converse of the Pythagorean Theorem.

Converse of the Pythagorean Theorem

For a triangle with sides of lengths a, b, and c, if the equation a^2+b^2=c^2 holds true, then the triangle is a right triangle with hypotenuse of length c.

Now, let's substitute A= 50, B= 120, and C= 130 into the formula and check if the equation holds true.
A^2+B^2=C^2
50^2+ 120^2? = 130^2
2500+14 400? =16 900
16 900=16 900 âś“
Since the equation holds true, the triangle formed by the forces is a right triangle. Therefore, the forces of 50 pounds and 120 pounds pull at right angles to each other.