Two tangents drawn to a circle from a point outside it, are equal in length.prove it.
1 answer:
Given: A circle with centre O; PA and PB are two tangents to the circle drawn from an external point P.
To prove: PA = PB
Construction: Join OA, OB, and OP.
It is known that a tangent at any point of a circle is perpendicular to the radius through the point of contact.
OA⊥PA
OB⊥PB
In △OPA and △OPB
∠OPA=∠OPB (Using (1))
OA=OB (Radii of the same circle)
OP=OP (Common side)
Therefor △OPA≅△OPB (RHS congruency criterion)
PA=PB
(Corresponding parts of congruent triangles are equal)
Thus, it is proved that the lengths of the two tangents drawn from an external point to a circle are equal.
The length of tangents drawn from any external point are equal.
So statement is correct
To prove: PA = PB
Construction: Join OA, OB, and OP.
It is known that a tangent at any point of a circle is perpendicular to the radius through the point of contact.
OA⊥PA
OB⊥PB
In △OPA and △OPB
∠OPA=∠OPB (Using (1))
OA=OB (Radii of the same circle)
OP=OP (Common side)
Therefor △OPA≅△OPB (RHS congruency criterion)
PA=PB
(Corresponding parts of congruent triangles are equal)
Thus, it is proved that the lengths of the two tangents drawn from an external point to a circle are equal.
The length of tangents drawn from any external point are equal.
So statement is correct
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Proportion which can be used to represent equivalency of 3 feet in 1 yard and 12 feet in 4 yard is 3 : 1 : : 12 : 4
<h3><u>Solution:</u></h3>Given that
There are 3 feet in one yard
And there are 12 feet in 4 yard
Number of feet in one yard = 3 that is feet : yard = 3 : 1
Number of feet in 4 yards = 12 that is feet : yard = 12 : 4
And 3 feet in 1 yard is equivalent to 12 feet in 4 yards means
That is 3 : 1 : : 12 : 4
A proportion is statement that two ratios are equal. It can be written in two ways: as two equal fractions a/b = c/d; or using a colon, a : b = c : d
Hence proportion which can be used to represent equivalency of 3 feet in 1 yard and 12 feet in 4 yard is 3 : 1 :: 12 : 4
Answer:
Step-by-step explanation:
Start by noticing that the angle is on the 4th quadrant (between
and
. Recall then that in this quadrant the functions tangent and cosine are positive, while the function sine is negative in value. This is important to remember given the fact that tangent of an angle is defined as the quotient of the sine function at that angle divided by the cosine of the same angle:
Now, let's use the information that the tangent of the angle in question equals "-1", and understand what that angle could be:
The particular special angle that satisfies this (the magnitude of sine and cosine the same) in the 4th quadrant, is the angle
which renders for the cosine function the value .
Now, since we are asked to find the value of the secant of this angle, we need to remember the expression for the secant function in terms of other trig functions:
Therefore the value of the secant of this angle would be the reciprocal of the cosine of the angle, that is: