Law of Cosine

Find QR

• 34.7 km
• 2.2 km
• 13.74
• 31.1 km

Tags

CCSS.HSG.SRT.D.10

CCSS.HSG.SRT.D.11

Find XZ

• 16.004 meters
• 544.165 meters
• 34.7 meters
• 1204.165 meters

Clint is building a wooden swing set for his children.  Each supporting end of the swing set is to be an A-frame constructed with two 10 foot long 4-by-4s joined at a 45 degree angle.  To prevent the swing set form tipping over, Clint wants to secure the base of each A-frame to concrete footings.  How far apart should the footings for each A-frame be?

• 5.461 feet
• 9.743 feet
• 6 feet
• 7.65 feet

Find BC

• A
• B
• C
• D

Which of the following formulas shows the Law of Cosines?

• $c^2=a^2+b^2-4ac+\cos\left(A\right)$

• $c^2=a^2-b^2-2ab\cos\left(C\right)$

• $c^2=a^2+b^2-2ab\cos\left(C\right)$

• $\frac{\cos\left(A\right)}{a}=\frac{\cos\left(B\right)}{b}=\frac{\cos\left(C\right)}{c}$

Find angle Z

• $20.145\degree$

• $71.232\degree$

• $51.055\degree$

• $57.713\degree$

Use Law of Cosines to find angle T

• $62.2\degree$

• $53.1\degree$

• $59.5\degree$

• $64.7\degree$

Use Law of Cosines to find XZ.

• 16.004 meters

• 544.165 meters

• 34.7 meters

• 1204.165 meters

What is the length of side x?

• 130 cm
• 112 cm
• 150 cm
• 105 cm