Example 1easy
8² + 17² = QR²
64 + 289 = QR²
353 = QR²
QR = √353 cm
What mistake did Rina make in her calculation?
- A)She incorrectly squared 8.
- B)She incorrectly squared 17.
- C)She assumed PR was a leg, but it is the hypotenuse.
- D)She should have subtracted the squares, not added them.
Step-by-step solution
- The right angle is at Q, so the side opposite Q, which is PR, must be the hypotenuse.
- According to the Pythagoras Theorem, (leg1)² + (leg2)² = (hypotenuse)².
- Rina incorrectly set up the equation as PQ² + PR² = QR². The correct equation should be PQ² + QR² = PR², since PR is the hypotenuse.
- Therefore, Rina made a mistake by assuming PR was a leg when it is the hypotenuse.
Answer: She assumed PR was a leg, but it is the hypotenuse.