In triangle RPQ, RP = 8.7 cm PQ = 5.2 cm Angle PRQ = 32° (a) Assuming that angle PQR is an acute angle, calculate the area of triangle RPQ? Give your answer correct to 3 significant figures

1 Answer
Feb 17, 2018

#22.6 cm^2(3 " s.f.")#

Explanation:

First, you have to find the angle #RPQ# by using the sine rule.

#8.7/5.2 = (sin \angleRQP)/sin32#

#sin \angleRQP = 87/52sin32#

#\angleRQP = 62.45#

#\therefore \angleRPQ = 180 - 62.45 - 32 = 85.55#

Now, you can use the formula,

#Area = 1/2ab sinC#
# = 1/2 * 8.7 * 5.2 * sin85.55#
# = 22.6 cm^2(3 " s.f.")#

P.S. Thank you @zain-r for pointing my mistake out