Answer:
a
Step-by-step explanation:
its right
For this, you have to understand the ratios of a 30,60,90 triangle. The ratio(in order) is x, x(sqrt 3), 2x (following the 30,60,90 pattern y'know). Well, we know the length of the hypotenuse, 4.2, so let's use ratios to figure the other sides out. The ratio of AC is x and the ratio of AB is 2x, so 2x/2=x=2.1. One side down. BC has a ratio of x(sqrt 3). We already know x so we can substitute it in. We get 2.1(sqrt 3). To calculate the area, use the formula 1/2(bh). Inputting the values in, we get 1/2(2.1*(2.1(sqrt 3)). This can be calculated to around 3.82. To calculate the perimeter, take the sum of the sides. By adding the sides together, we get about 9.98. Hope you can now understand how to do these kinds of questions.
The answer is 7x+21
Explanation: you have to distribute 7into c and three. So you would multiply 7 by x (or 1x) and 7 times 1 is 7 so it would be 7x and then you would multiply 7 times 3 which is 21 and there are no like terms with 7x and 21 so it’s just 7x+21
Answer:
50.28 sq. cm.
Step-by-step explanation:
A and B are centers of two circles of radii 8 cm and 1 cm such that AB =13 cm.
Now, angle ACB =90 degree where C is the center of another circle which touches the above two circles.
Now, ABC forms a right triangle where AB = 13 cm, AC = (r + 8) cm and BC = (1 + r) cm.
{Where r is the radius of the circle C.
Applying Pythagoras Theorem. AB² = AC² + BC²
⇒ 13² = (r + 8)² + (r + 1)²
⇒ 169 = r² + 16r + 64 + f² + 2r + 1
⇒ 2r² + 18r - 104 = 0
⇒ r² + 9r - 52 = 0
⇒ (r + 13)(r - 4) = 0
Hence, r = 4 {As the value of r can not be negative}
Therefore, the area of the circle C is π(4)² = 50.28 sq. cm. (Answer)
