Advertisement Remove all ads

Find the Area of a Triangle, Whose Sides Are : 21 M, 28 M and 35 M - Mathematics

Sum

Find the area of a triangle, whose sides are :

21 m, 28 m, and 35 m

Advertisement Remove all ads

Solution

Sides of ∆ are
a = 21 m
b = 28 m
c = 35 m

S = `(a + b + c)/2 = (21 + 28 + 35)/2`

= `84/2 = 42`

area of Δ = `sqrt(S(S - a)(S - b)(S - c))`

= `sqrt(42(42 - 21)(42 - 28)(42 - 35))`

= `sqrt(42 xx 21 xx 14 xx 7)`

= `sqrt(7 xx 3 xx 2 xx 3 xx 7 xx 2 xx 7 xx 7)`

= `sqrt(7 xx 7 xx 7 xx 7 xx 3 xx 3 xx 2 xx 2)`

= `7 xx 7 xx 3 xx 2 = 294  "m"^2`

Concept: Perimeter of Triangles
  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

Selina Concise Mathematics Class 8 ICSE
Chapter 20 Area of a Trapezium and a Polygon
Exercise 20 (A) | Q 1.3 | Page 223
Advertisement Remove all ads
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×