Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 2D

Question:

The area of a circular park is very nearly equal to seven-fifteenth of the area of a triangular field having sides 110 m. 600 m and 610 m. What is the diameter of the park? (Take $π=\frac{22}{7}$)

Options:

160 m

120 m

150 m

140 m

Correct Answer:

140 m

Explanation:

We know that,

Area of right angled triangle = \(\frac{1}{2}\) × Base × Height

Area of circle = πr2

We have,

The sides of the triangle are 110 m, 600 m, and 610 m.

Area of circular park = \(\frac{7}{15}\) × Area of the triangular field

Area of right angled triangle = \(\frac{1}{2}\) × 600 × 110  = 33000

Area of circular park = \(\frac{7}{15}\) × 33000 = 15400

= πr2 = 15400

= \(\frac{22}{7}\) × r2 = 15400

= r2 = 15400 × \(\frac{7}{22}\)

= r = \(\sqrt {4900}\) = 70m

Diameter of circular park = 2 × 70 = 140 m