A triangle has sides 35 cm ,54 cm ,and 61 cm long . Find its area . Also find the smallest of its altitude
Answers
Here,
Sides = 35 cm, 54 cm & 61 cm
Assume
Sides,
a = 35 cm
b = 54 cm
c = 61 cm
Now,
Semi Perimeter of the Triangle,
s = (a + b + c)/2
s = (35 + 54 + 61)/2
s = 150/2
s = 75 cm
Now,
Using Heron formula :-
A = √s(s - a)(s - b)(s - c)
A = √75(75 - 35)(75 - 54)(75 - 61)
A = √75 × 40 × 21 × 14
A = √(25 × 3) × (10 × 4) × (3 × 7) × (2 × 7)
A = √25 × 4 × (3 × 3) × (7 × 7) × (2 × 5) × 2
A = √25 × 4 × (3 × 3) × (7 × 7) × (2 × 2) × 5
A = 5 × 2 × 3 × 7 × 2 √5
A = 420 √5
A = 420 × 2.236
A = 939.15 cm²
Now
Side 54 cm :-
Area of triangle,
A = ½ x Base x altitude
939.15 = ½ × 54 × altitude
altitude = (939.15 × 2)/54
altitude = 34.78 cm
Also,
Side 35 cm :-
Now,
Area of triangle,
A = ½ x Base x altitude
939.15 = ½ × 35 × altitude
altitude = (939.15 × 2)/35
altitude = 53.66 cm
Side 61 cm :-
Now,
Area of triangle,
A = ½ x Base x altitude
939.15 = ½ × 61 × altitude
altitude = (939.15 × 2)/61
altitude = 30.79 cm
Smallest altitude = 30.79 cm