Answer :
Answer:
C
Step-by-step explanation:
(i)
given a triangle with 2 sides and the included angle known
to find the third side use the Cosine rule
a² = b² + c² - 2bc cosA
adapting the formula to describe Δ PQR
r² = p² + q² - 2pq cosR
here r = PQ, p = QR = 7.6 , q = PR = 8.4 and ∠ R = 62° , then
r² = 7.6² + 8.4² - (2 × 7.6 × 8.4 × cos62° )
= 57.76 + 70.56 - 59.942
= 128.32 - 59.942
= 68.376 ( take square root of both sides )
r = [tex]\sqrt{68.378}[/tex]
≈ 8.27
that is PQ ≈ 8.27 cm ( to 2 decimal places )
(11)
the area (A) is then calculated as
A = [tex]\frac{1}{2}[/tex] pq sinR
= 0.5 × 7.6 × 8.4 × sin62°
≈ 28.2
that is area of Δ PQR ≈ 28.2 cm² ( to 1 decimal place )
Answer:
c
Step-by-step explanation:
I think it's c I might be wrong though not sure