Name: ____________________________________
1. If a = 14, e = 16, and m ∠ C = 30, find the area of ΔACE.
a. 56
b. 56
c. 112
d. 112
2. In ΔNEW, m ∠ N = 60, NE = 8, and NW = 6. Find the area of ΔNEW.
a. 12
b. 12
c. 24
d. 24
3. The area of ΔABC is 20. If a = 10 and b = 8, find the measure of acute angle C.
a. 30
b. 45
c. 60
d. 75
4. The vertex of isosceles triangle ABC measures 30°, and each leg has length 20. What is the area of ΔABC?
a. 100
b. 100
c. 100
d. 200
5. In triangle ABC, a = 4, and m ∠ C = 30. If the area of the triangle is 6, what is the length of side b?
a. 6
b. 2
c. 12
d. 4
6. The area of triangle ABC is 42. If AB = 8 and m∠B = 61, the length of a. 5.1
b. 9.2
c. 12.0
d. 21.7
is approximately
7. An obtuse angle of a parallelogram has a measure of 150°. If the sides of the parallelogram measure 10 and 12 centimeters,
what is the area of the parallelogram?
a. b. c. d. 30 cm2
60 cm2
60
cm2
60
cm2
8. What is the area of a parallelogram that has sides measuring 8 cm and 12 cm and includes an angle of 120°?
a. 24
b. 48
c. 83
d. 96
9. Find, to the nearest tenth of a square foot, the area of a rhombus that has a side of 6 feet and an angle of 50°.
10. Two sides of a triangular-shaped sandbox measure 22 feet and 13 feet. If the angle between these two sides measures 55°,
what is the area of the sandbox, to the nearest square foot?
a. 82
b. 117
c. 143
d. 234
11. In parallelogram BFLO, OL = 3.8, LF = 7.4, and m∠O = 126. If diagonal a. 11.4
b. 14.0
c. 22.7
d. 28.1
is drawn, what is the area of ΔBLF?
12. The sides of a parallelogram measure 10 cm and 18 cm. One angle of the parallelogram measures 46 degrees. What is the
area of the parallelogram, to the nearest square centimeter?
a. 65
b. 125
c. 129
d. 162
Answer Key for Area of a Triangle
1. a
2. b
3. a
4. a
5. a
6. c
7. b
8. b
9.
A rhombus is also a parallelogram, so we can use the formula for the area of a parallelogram, which is adapted from the general
area of a triangle: Areaparallelogram = ab sin C. Below is a sketch of the rhombus using the given information.
a = b = 6 because all sides of a rhombus are the same length. C = 50°. Substitute the values into the area formula and evaluate.
Area = (6)(6) sin 50° = 27.5775
To the nearest tenth of a square foot, the area of the rhombus is 27.6 square feet.
10. b
11. a
12. c