In triangle PQR, q= 8cm ,r=6cm and cos p=1/12. calculate the value of p

1 answer

Careful about your notation.
Conventional notation is to refer to sides of a figure using small letters
and capital letters when referring to the vertices or angles of a triangle
So you meant to say: cos P = 1/12

anyway ....
you have the cosine law here,
p^2 = q^2 + r^2 - 2qr cosP
= 64 + 36 - 2(8)(6)(1/12)
= 92
So p = √92 = appr 9.59