Math Core

Unit 8 · Test

Unit 8 test: Oblique Triangles

13 questions. Answer them all, then submit to see your score. Solutions unlock after you submit.

This test covers the law of sines, the ambiguous case (SSA), the law of cosines, and the area of a triangle from two sides and an angle or from three sides (Heron's formula).

Question 1

In triangle ABCABC, A=38∘A = 38^\circ, B=72∘B = 72^\circ and a=15a = 15. Find bb to the nearest tenth.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 2

In triangle ABCABC, A=44∘A = 44^\circ, C=68∘C = 68^\circ and b=25b = 25. Find aa to the nearest tenth.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 3

How many triangles have A=55∘A = 55^\circ, a=8a = 8 and b=12b = 12?

Question 4

How many triangles have A=36∘A = 36^\circ, a=7a = 7 and b=10b = 10?

Question 5

For the triangle data in the previous question (A=36∘A = 36^\circ, a=7a = 7, b=10b = 10), find all possible values of angle BB to the nearest tenth of a degree. Separate answers with a comma.

Separate answers with commas, e.g. 2, -5

Question 6

How many triangles have A=120∘A = 120^\circ, a=10a = 10 and b=6b = 6?

Question 7

In triangle ABCABC, b=9b = 9, c=13c = 13 and A=47∘A = 47^\circ. Find aa to the nearest tenth.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 8

A triangle has sides 66, 88 and 1111. Find its largest angle to the nearest tenth of a degree.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 9

In triangle ABCABC you know sides aa and bb and angle CC. What is the best first step to solve the triangle?

Question 10

A triangle has sides a=11a = 11 and b=16b = 16 with C=58∘C = 58^\circ between them. Find its area to the nearest tenth.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 11

Use Heron's formula to find the area of a triangle with sides 1111, 1313 and 2020.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 12

To find the distance ABAB across a lake, a surveyor stands at point CC and measures CA=320CA = 320 m, CB=410CB = 410 m, and ∠ACB=72∘\angle ACB = 72^\circ. Find ABAB to the nearest meter.

Points A and B are on opposite sides of a lake.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 13

Lookout towers PP and QQ are 1212 miles apart. A signal flare FF is sighted at an angle of 48∘48^\circ from line PQPQ at tower PP and 63∘63^\circ from line PQPQ at tower QQ. How far is the flare from tower PP, to the nearest tenth of a mile?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.