Class 09 | Ganita Manjari 01 | Ch. 06 Measuring Space Perimeter and Area Solutions
Class 9 Maths Ganita Manjari Chapter 6 Solutions Measuring Space Perimeter and Area Think and Reflect (NCERT Textbook Page No. 127) Q. 1. What is the difference in radius between the first and second lanes? Use the Fig. 6.11 to find the stagger needed by the runner in the second lane. Will an equal stagger be needed between the third and second lanes? Sol. The extra distance in an outer lane is created only on the curves. The distance of a circular path is C = 2πr For the lane 1, r 1 = 36.5 m and width, w = 1.22 m If Lane 2 has a radius that is w (lane width) metres larger than Lane 1, the extra distance for one full circle (360°) is = 2π(r1 + w) – 2πr1 =2πr1 + 2πw –2πr1 = 2π w =2× {22}{7} × 1.22 = 7.67 m Yes. Because the width of each lane is constant (1.22 m), the difference in radius between Lane 3 and Lane 2 is the same as the difference between Lane 2 and Lane 1. Think and Reflect (NCERT Textbook Page No. 131) Q. 1. The area of a rectangle can ...