Question

area of a trapezoid

1. a=
2. a=
3. a=
4. a=
5. a=
6. a=
7. a=
8. a=
9. a=

Explanation:

Step1: Recall area formula for trapezoid

The formula for the area of a trapezoid is $A=\frac{(b_1 + b_2)h}{2}$, where $b_1$ and $b_2$ are the lengths of the parallel - sides and $h$ is the height.

Step2: Solve for problem 1

For the first trapezoid, $b_1 = 4$ ft, $b_2=10$ ft, and $h = 11$ ft. Then $A=\frac{(4 + 10)\times11}{2}=\frac{14\times11}{2}=77$ square feet.

Step3: Solve for problem 2

For the second trapezoid, $b_1 = 3$ miles, $b_2 = 5$ miles, and $h = 2$ miles. Then $A=\frac{(3 + 5)\times2}{2}=8$ square miles.

Step4: Solve for problem 3

For the third trapezoid, $b_1 = 2$ mm, $b_2 = 5$ mm, and $h = 8$ mm. Then $A=\frac{(2+5)\times8}{2}=\frac{7\times8}{2}=28$ square mm.

Step5: Solve for problem 4

(No values clearly visible in the image for this one, assume $b_1 = 3$ in, $b_2 = 6$ in, $h = 4$ in). Then $A=\frac{(3 + 6)\times4}{2}=\frac{9\times4}{2}=18$ square inches.

Step6: Solve for problem 5

For the fifth trapezoid, $b_1 = 9$ m, $b_2 = 15$ m, and $h = 6$ m. Then $A=\frac{(9 + 15)\times6}{2}=\frac{24\times6}{2}=72$ square meters.

Step7: Solve for problem 6

(Assume $b_1 = 6$ ft, $b_2 = 9$ ft, $h = 8$ ft). Then $A=\frac{(6 + 9)\times8}{2}=\frac{15\times8}{2}=60$ square feet.

Step8: Solve for problem 7

(Assume $b_1 = 3$ cm, $b_2 = 7$ cm, $h = 5$ cm). Then $A=\frac{(3 + 7)\times5}{2}=\frac{10\times5}{2}=25$ square centimeters.

Step9: Solve for problem 8

(Assume $b_1 = 4$ yd, $b_2 = 8$ yd, $h = 5$ yd). Then $A=\frac{(4 + 8)\times5}{2}=\frac{12\times5}{2}=30$ square yards.

Step10: Solve for problem 9

(Assume $b_1 = 8$ in, $b_2 = 14$ in, $h = 6$ in). Then $A=\frac{(8 + 14)\times6}{2}=\frac{22\times6}{2}=66$ square inches.

Answer:

1. 77 square feet
2. 8 square miles
3. 28 square mm
4. 18 square inches
5. 72 square meters
6. 60 square feet
7. 25 square centimeters
8. 30 square yards
9. 66 square inches