Question

Solve and explain question

Answer 1

∠ P = 60°

Explanation:

using the Cosine law in Δ ABC

cos A =
`(b^2+c^2-a^2)/(2bc)`

where b and c are the sides adjacent to ∠ A and a is the side opposite ∠ A

here a = 7 , b = 8 , c = 5 and ∠ P = ∠ A

cos P =
`(8^2+5^2-7^2)/(2(8)(5))`

=
`(64+25-49)/(80)`

=
`(40)/(80)`

=
`(1)/(2)`

then

∠ P =
`cos^(-1)` (
`(1)/(2)` ) = 60°