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MATH / Triangles BDC and ACD are coplanar and isosceles. If we have m∠ABC=70^(∘), what is m∠BAC, in degrees? [asy] unitsize(2 cm); defaultpen(linewidth(1pt)+fontsize(10pt)); pair a,b,c,d;…

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Answer published by the source. Consult the official source to check your work against its answer.

problem

Triangles BDCBDC and ACDACD are coplanar and isosceles. If we have m∠ABC=70∘m\angle ABC = 70^\circ, what is m∠BACm\angle BAC, in degrees? [asy] unitsize(2 cm); defaultpen(linewidth(1pt)+fontsize(10pt)); pair a,b,c,d; b = (0,0); c = (1,0); d = c+dir(140); a = d+dir(70); draw(a--b--c--cycle); draw(d--c); pair s,t; s = (.5,0)+(0,.05); t = (.5,0)+(0,-.05); draw(s--t); s = .5*(c+d) + .05*dir(50); t = .5*(c+d) - .05*dir(50); draw(s--t); s = .5*(a+d) + .05*dir(160); t = .5*(a+d) - .05*dir(160); draw(s--t); label("A",a,N); label("B",b,SW); label("C",c,SE); label("D",d,NW); label("70∘70^\circ",b+(.05,.03),NE); [/asy]
Plain-text mathematical notation (without MathML)
Triangles BDC and ACD are coplanar and isosceles. If we have m∠ABC=70^(∘), what is m∠BAC, in degrees?

[asy]
unitsize(2 cm);

defaultpen(linewidth(1pt)+fontsize(10pt));
pair a,b,c,d;
b = (0,0);
c = (1,0);
d = c+dir(140);
a = d+dir(70);
draw(a--b--c--cycle);
draw(d--c);
pair s,t;
s = (.5,0)+(0,.05);
t = (.5,0)+(0,-.05);
draw(s--t);
s = .5*(c+d) + .05*dir(50);
t = .5*(c+d) - .05*dir(50);
draw(s--t);
s = .5*(a+d) + .05*dir(160);
t = .5*(a+d) - .05*dir(160);
draw(s--t);
label("A",a,N);
label("B",b,SW);
label("C",c,SE);
label("D",d,NW);
label("70^(∘)",b+(.05,.03),NE);
[/asy]
Original LaTeX notation
Triangles $BDC$ and $ACD$ are coplanar and isosceles. If we have $m\angle ABC = 70^\circ$, what is $m\angle BAC$, in degrees?

[asy]
unitsize(2 cm);

defaultpen(linewidth(1pt)+fontsize(10pt));
pair a,b,c,d;
b = (0,0);
c = (1,0);
d = c+dir(140);
a = d+dir(70);
draw(a--b--c--cycle);
draw(d--c);
pair s,t;
s = (.5,0)+(0,.05);
t = (.5,0)+(0,-.05);
draw(s--t);
s = .5*(c+d) + .05*dir(50);
t = .5*(c+d) - .05*dir(50);
draw(s--t);
s = .5*(a+d) + .05*dir(160);
t = .5*(a+d) - .05*dir(160);
draw(s--t);
label("A",a,N);
label("B",b,SW);
label("C",c,SE);
label("D",d,NW);
label("$70^\circ$",b+(.05,.03),NE);
[/asy]

level

Level 2

type

Geometry

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