Advertisements
Advertisements
Question
Find the area of triangle with following sides. [All measures are in cm.]
17, 25, 28
Sum
Advertisements
Solution
Given:
Sides of the triangle are 17 cm, 25 cm, 28 cm.
Step 1: Calculate the semi-perimeter (s)
`s = (a + b + c)/2`
= `(17 + 25 + 28)/2`
= `70/2`
= 35 cm
Step 2: Use Heron’s formula to find the area (A)
`A = sqrt(s(s - a)(s - b)(s - c))`
= `sqrt(35(35 - 17)(35 - 25)(35 - 28))`
= `sqrt(35 xx 18 xx 10 xx 7)`
Calculate inside the square root:
35 × 18 = 630
630 × 10 = 6300
6300 × 7 = 44100
Step 3: Calculate the square root
`A = sqrt(44100)`
A = 210 cm2
The area of the triangle with sides 17 cm, 25 cm and 28 cm is 210 cm2.
shaalaa.com
Is there an error in this question or solution?
Chapter 17: Mensuration - EXERCISE 17A [Page 201]
