Da answer is cCbecause it is
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Answer:
∠CAB = 28°
∠DAC = 64°
Step-by-step explanation:
What you do in each case is make use of the relationships you know about angles in a triangle and around parallel lines. You can also use the relationships you know about diagonals in a rectangle, and the triangles they create.
<u>Left</u>
Take advantage of the fact that ∆AEB is isosceles, so the angles at A and B in that triangle are the same. If we call that angle measure x, then we have the sum of angles in that triangle is ...
x + x + ∠AEB = 180°
2x = 180° -124° = 56°
x = 28°
The measure of angle CAB is 28°.
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<u>Right</u>
Sides AD and BC are parallel, so diagonal AC can be considered a transversal. The two angles we're concerned with are alternate interior angles, so are congruent.
∠BCA = ∠DAC = 64°
The measure of angle DAC is 64°.
(Another way to look at this is that triangles BCE and DAE are congruent isosceles triangles, so corresponding angles are congruent.)
Answer:
10.5 cm
Step-by-step explanation:
Volume = base area × height
798 = (9.5 × 8) × height
height = 798/76
height = 10.5
Answer:
7. 1520.53 cm²
8. 232.35 ft²
9. 706.86 m²
10. 4,156.32 mm²
11. 780.46 m²
12. 1,847.25 mi²
Step-by-step explanation:
Recall:
Surface area of sphere = 4πr²
Surface area of hemisphere = 2πr² + πr²
7. r = 11 cm
Plug in the value into the appropriate formula
Surface area of the sphere = 4*π*11² = 1520.53 cm² (nearest tenth)
8. r = ½(8.6) = 4.3 ft
Plug in the value into the appropriate formula
Surface area of the sphere = 4*π*4.3² = 232.35 ft² (nearest tenth)
9. r = ½(15) = 7.5 m
Surface area of the sphere = 4*π*7.5² = 706.86 m² (nearest tenth)
10. r = ½(42) = 21 mm
Plug in the value into the formula
Surface area of hemisphere = 2*π*21² + π*21² = 2,770.88 + 1,385.44
= 4,156.32 mm²
11. r = 9.1 m
Plug in the value into the formula
Surface area of hemisphere = 2*π*9.1² + π*9.1² = 520.31 + 260.15
= 780.46 m²
12. r = 14 mi
Plug in the value into the formula
Surface area of hemisphere = 2*π*14² + π*14² = 1,231.50 + 615.75
= 1,847.25 mi²