Question

Triangle DEF has side lengths d= 7.1 and f= 26.5. The measure of angle E is 13°. What is the length of side e? 31.9 19.6 4.7 162.3

Answer 1

Answer:

19.6

Step-by-step explanation:

According to the

Cosine Theorem

e² = d² + f² - 2dfcos /_E

°Cos 13° = 0.974

e² = (7.1) 2 + (26.5) 2-2 × 26 = 5 × 7.1 × 0.974

=752.66 - 366.516

= 386.14

e = 386.14 = 19.6