Question

50 points, basic math, about areas
Can somebody please give me the answers to these?

Answer 1

1. 70 units²

2. 23 units²

3. 442.5 units²

4. 289 units²

5. 632 units²

Explanation:

1. (8×8) + (3×2) = 64 + 6 = 70

2. (6×3) + (1×1) + (2×2) = 18 + 1 + 4 = 23

3. (11×15) + (11×15) + ½(15×15)

165 + 165 × 112.5 = 442.5

4. ½(6×15) + ½(7×8) + (18×12)

45 + 28 + 216 = 289

5. (28×24) - ½(10×8)

672 - 40 = 632

Answer 2

1. 70.

2. 29.

3. 442.5

4. 289.

5. 632.

Explanation:

The key to doing these is to split the polygons into rectangles, triangles or trapezoids as appropriate.

For example, number 1 consists of a rectangle area 8 * 8 and another of 3* 2.

So the area = 64 + 6 = 70 unit^2.

2. The area = sum of 3 rectangles 1*1 + 4*6 + 2*2.

3. Area = 11*15 + 11*15 + 1/2*15*15

4. Area = 18*12 + 1/2 * 6 * 15 + 1/2 * 7 * 8.

5. Area = area of 2 rectangles + area of a trapezoid.

= 18 * 24 + 4*10 + 1/2(12 + 20) * 10.