Consider, in ΔRPQ,
RP = R (Radius of larger circle)
PQ = r (radius of smaller circle)
We have to find, RQ, by Pythagoras theorem,
RP² = PQ²+RQ²
R² = r²+RQ²
RQ² = R²-r²
RQ = √(R²-r²
Now, as RQ & QS both are tangents of the smaller circle, their lengths must be equal. so, RS = 2 × RQ
RS = 2√(R²-r²)
Answer:
x = 4√5
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
<u>Trigonometry</u>
- Pythagorean Theorem: a² + b² = c²
Step-by-step explanation:
<u>Step 1: Define</u>
We are given a right triangle. We can use Pythagorean Theorem.
a = 19
b = x
c = 21
<u>Step 2: Find </u><em><u>x</u></em>
- Substitute: 19² + x² = 21²
- Isolate <em>x</em> term: x² = 21² - 19²
- Evaluate: x² = 441 - 361
- Subtract: x² = 80
- Isolate <em>x</em>: x = √80
- Simplify: x = 4√5
And we have our final answer!
Surface area =
=
x 3.14 x 3 x 3 x 3 = 3.14 x 4 x 3 x 3 = 113.04 yd^2 = approx. 113.1 yd^2
The answer is 36 because in order to find area you multiply length and width so:
A= L x W
9 x 4 = 36
Answer:
x = -4
Step-by-step explanation:
5x-9 = 15+11x
5x - 11x = 15 + 9
-6x = 24
x = -4