find the area of triangle ABD

Question

anonymous · Answer

attachment

anonymous · Answer

@sdfgsdfgs

sdfgsdfgs · Answer

BD is a tangent so wat that tells u about Angle ABD?

anonymous · Answer

im not sure. :/

anonymous · Answer

its not a right triangle

sdfgsdfgs · Answer

well...think again....wats is a tangent?

anonymous · Answer

a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.

sdfgsdfgs · Answer

specifically tangent in relation to a radius at the same pt

anonymous · Answer

yes.

sdfgsdfgs · Answer

ok let me put it this way - why u dont think its a right angle?

anonymous · Answer

|dw:1430160135400:dw|

none of the angles are 90 degrees.

sdfgsdfgs · Answer

hahhaaa cuz' u didnt draw it right :P

anonymous · Answer

close enough lol so it is a right triangle? it doesnt look that way

sdfgsdfgs · Answer

OK my drawing is worse :(

anonymous · Answer

its okay lol how do i go about solving this one?

sdfgsdfgs · Answer

so yes, plz take my word 4 it - angle ABD is a right angle lol

anonymous · Answer

okay i trust you :)

sdfgsdfgs · Answer

so if its a right angle, then the area of the triangle is given by what?

anonymous · Answer

$$\frac{ h*b }{ 2 }$$

sdfgsdfgs · Answer

OK looking at the drawing, what is b for triangle ABD?

anonymous · Answer

the hypotenuse or neither. 

A is the base and D is the height.

sdfgsdfgs · Answer

back up 4 a sec: h is height n b is base in ur eqn above right?

anonymous · Answer

yes lol

sdfgsdfgs · Answer

so let me ask again - what is the base of ABD when u know ABD is a right angle?

anonymous · Answer

90 degrees?

sdfgsdfgs · Answer

hahahaa correct - should have said what is the base of triangle ABD when u know angle ABD is 90deg.?

anonymous · Answer

how do i figure the length out with only knowing the degree? is the height 11? lol 7+4

sdfgsdfgs · Answer

relax plz? :)

draw this n label b n h on here

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anonymous · Answer

|dw:1430161345778:dw|

sdfgsdfgs · Answer

GOOD :) now compare to the drawing in ur question, what is b equal to?

anonymous · Answer

A?

anonymous · Answer

which is the radius so 7 ?

sdfgsdfgs · Answer

BINGO :) one down n now we need to find h....

sdfgsdfgs · Answer

but h is a lil more complicated....its not given.

what other length we know about triangle ABD though?

anonymous · Answer

well the radius of c is 4 so that is 8. and then the radius of a is 7 so 7+8

sdfgsdfgs · Answer

also correct n remember ABD is a right-angled triangle so h can be found by....

anonymous · Answer

a^2 + 7^2 = c^2 ?

okay so that makes the area 52.5

anonymous · Answer

or 53 in this case?

sdfgsdfgs · Answer

slow down!!! u going too fast 4 me :P

so what is h plz?

anonymous · Answer

h=15

anonymous · Answer

$$\frac{ 15*7 }{ 2 }$$

anonymous · Answer

$$\frac{ 105 }{ 2 }$$

anonymous · Answer

$$105\div2=52.5$$

sdfgsdfgs · Answer

nope....read ur eqn again about a^2 + b^2 = c^2

which one is a, b n c in this case?

anonymous · Answer

a^2 = base
b^2 = height 
c^2 is the unknown side (hypotenuse)

sdfgsdfgs · Answer

compare the triangle u drawn n ABD in the question....are u sure about that?

sdfgsdfgs · Answer

ok wait....what u wrote above is right....but.....

sdfgsdfgs · Answer

c is the hypotense but its not unknown....what is c equal to in triangle ABD?

anonymous · Answer

side BD

sdfgsdfgs · Answer

hypotense is the longest side of a right-angle triangle and it is the side facing the right angle....

anonymous · Answer

yes thats side BD correct

sdfgsdfgs · Answer

where is the right angle n which side it is facing in triangle ABD?

anonymous · Answer

|dw:1430162587081:dw|

anonymous · Answer

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