In a triangle , the length of the first side is 5 cm less than the length of the second side . The length of the third side is 7 cm more than the length of the first side if the first side is of length is 18 cm , then what is the semiperimeter of the triangle?
Answers
Answer:
⇒ The sum of the lengths of any two sides in a triangle is always greater than the length of the third side in the triangle.
⇒ The differnce of the lengths of any two sides in a triangle is always lesser than the length of the third side in the triangle.
⇒ The difference between 4cm and 7cm is
3cm and their sum is 11cm.
⇒ To ensure that the above mentioned rule is not violated, the possible length of the third side has got to be greater than 3cm and lesser than 11cm.
⇒ So from the given options 6cm is less than
11cm and greater than 3cm
∴ The length of the third side of triangle is 6cm
Given :-
A triangle the length of the first side is 5 cm less than the length of the second side . The length of the third side is 7 cm more than the length of the first side if the first side is of length is 18 cm ,
To Find :-
Semi-perimeter
Solution :-
Let the second side be 'b' and third side be 'c'
When the second side is 5 cm less than other
b = 18 - 5
b = 13 cm
Now
c = 18 + 7
c = 25
Sides of triangles are 25 cm,13 cm,18 cm
Now
Semi perimeter = a + b + c/2
S = 18 + 13 + 25/2
S = 18 + 38/2
S = 56/2
S = 28 cm
Semi-perimeter is 28 cm
Hope it helps you