The perimeter of a triangular field is 120m. Two of the sides are 21m and 40m. Calculate the largest angle of the field.

the largest angle of the field is 149⁰

Step-by-step explanation:

Given;

perimeter of the triangular filed, P = 120 m

length of two known sides, a and b = 21 m and 40 m respectively

The length of the third side is calculated as follows;

a + b + c = P

21 m  + 40 m  + c = 120 m

61 m +  c = 120 m

c = 120 m - 61 m

c = 59 m

                         B

                     ↓            ↓  

                  ↓                          ↓

                ↓                                       ↓

            A →  →  → →  →  → →  → →    →    →  C

Consider ABC as the triangular field;

Angle A is calculated by applying cosine rule;

Angle B is calculated as follows;

Angle C is calculated as follows;

Therefore, the largest angle of the field is 149⁰.

7.3

step-by-step explanation: