CAT Quantitative Aptitude Questions | Geometry Questions for CAT - Triangles

CAT Questions

The question is from Geometry - Right triangle. It tests our understanding of right triangle properties. CAT Geometry questions are heavily tested in CAT exam. Make sure you master Geometry problems. From before the time, Pythagorus said "Let me call this third thing as Hypotenuse", mathematicians have been enamoured with right triangles.

Question 10: Consider a right–angled triangle with inradius 2 cm and circumradius of 7 cm. What is the area of the triangle?

1. 32 sq cms
2. 31.5 sq cms
3. 32.5 sq cms
4. 33 sq cms

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Video Explanation

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Explanatory Answer

Method of solving this CAT Question from Triangles: Let's start with the given details.

r = 2
R = 7 (Half of hypotenuse)
Hypotenuse = 14
r = (a + b - h)/2
2 = (a + b - 14)/2
a + b - 14 = 4
a + b = 18
a² + b² = 14 ²
a² + (18 - a)² = 14 ²
a² + 324 + a² - 36a = 196
2a² - 36a + 128 = 0
a² - 18a + 64 = 0
Now the 2 roots to this equation will effectively be a, 18 – a. Product of the roots = 64.
Area = 1/2 * product of roots (How? Come on, you can figure this out.)
= 32 sq. cms

The question is "What is the area of the triangle?"

Hence, the answer is 32 sq. cms

Choice A is the correct answer.