Answer: i'm pretty sure it's option A
9514 1404 393
Answer:
75 in^2
Step-by-step explanation:
The central vertical rectangle (including "ears") has dimensions
3 in wide by (9+2+2) = 13 in tall
Its area is
A = LW = (3 in)(13 in) = 39 in^2
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The two rectangles either side of that have dimensions 2 in by 9 in. The area of each of them is
A = LW = (2 in)(9 in) = 18 in^2
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The total net area is the sum of the areas of the parts:
left rectangle + central rectangle + right rectangle
= 18 in^2 + 39 in^2 + 18 in^2 = 75 in^2 . . . . surface area of the net
Answer:
8x^4+9x^3+4x-1
Step-by-step explanation:
(6x^3 – 5x^2 + 3x – 5) + (8x^4 + 3x^3 + 5x^2 + x + 4)
Group like terms
8x^4+6x^3+3x^3-5x^2+5x^2+3x+x-5+4
8x^4+9x^3+4x-1
You found CD from the Pythagorean theorem to be ...
... CD = √(5² -2²) = √21
Since triangle ADC ~ triangle ACB, the ratios of corresponding sides are the same:
... AC/AD = AB/AC
... AB = AC²/AD
... AB = 5²/2 = 12.5 . . . . . . . the base of the overall triangle
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Then the area (A) is ...
... A = (1/2)bh
... A = (1/2)(12.5)(√21) ≈ 28.64 square units
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As you see here, the altitude of a right triangle divides it into three similar triangles. From smallest to largest, they are ...
... ADC ~ CDB ~ ACB
You can figure this using AAA similarity, since the smallest and largest triangles listed above share an acute angle vertex (∠A). That, together with the right angle, means all angles are congruent. After that, then you know ∠ACD ≅ ∠CBD, so you can show the middle sized triangle is similar to the other two.
The answer would be B. All you would do is subtract 6.4 - 2.06 and you would annex a zero after the four. Then you would get 4.34
