MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12
        The sides of a triangle are in AP and its area is 3 / 5 of an equilateral triangle of the same perimeter prove that the lebgth of the sides are 3:5:7, and find the gratest angle of the triangle.
2 years ago

Answers : (1)

Suraj kumar
21 Points
							Let sides be a-d,a,a+d therefore s=3a/2 Area = √3a/2(3a/2 - a)(3a/2 -a+d)(3a/2 -a-d)= 3/5×√3/4 a^2 On solving we get a/4×√a^2 -4d^2 = 3/5×a^2/4 Further 16a^2=100d^2 =4a=10d or 2a=5d hence ratio -a-d:a:a+d = 3:5:7 (a-2a/5:a:a+2a/5) And greatest angle = (3a)^2+(5a)^2 - (7a)^2/2×3a×5a = cosA On solving cosA= -1/2 hence A = 120°
						
11 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 31 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details