Free help with homework

Why join Brainly?

  • ask questions about your assignment
  • get answers with explanations
  • find similar questions

Two circles of radius 15 cm and 20 cm respectively have the distance between their centres as 25. what is the length of the common chord ?



The Brainliest Answer!
First, notice that 15,20,25 is produced by the primitive pythagorean triple (3,4,5), so it is a right triangle and the area is obtained by simply multiplying the legs and dividing by 2 :
Area = \frac{15*20}{2}=150

Another way to obtain the same area is by considering 25 as base, then the height is half of the common chord; call the height, l/2 :
Area = \frac{25*l/2}{2}=\frac{25l}{4}

Set both areas equal to each other and solve the length of common chord, l :
2 4 2
450 = 50x
oh my gosh i was writing 225x2 as 500 :( sorry for wasting ur time
Haha np :) i like ur method more than mine
urs is shorter more preferrable thanks alot!
The Brain
  • The Brain
  • Helper
Not sure about the answer?
Learn more with Brainly!
Having trouble with your homework?
Get free help!
  • 80% of questions are answered in under 10 minutes
  • Answers come with explanations, so that you can learn
  • Answer quality is ensured by our experts