Question

ABCD is a square. What is the measure of angle BAC?

A. 90°
B. 45°
C. 15°
D. 135°

Answer 1

The correct option is B.

Explanation:

Given information: ABCD is a square.

According to the property of square,

1. The measure of all interior angles of the square is 90°.

2. Diagonals are angle bisector.

In the given figure ABCD is square, so

`\angle DAB=90^(\circ)`

AC is a diagonal of ABCD.

`\angle DAC=\angle BAC`

We can say that

`\angle DAB=\angle DAC+\angle BAC`

`\angle DAB=\angle BAC+\angle BAC`

`\angle DAB=2\angle BAC`

`90^(\circ)=2\angle BAC`

Divide both sides by 90.

`(90^(\circ))/(2)=\angle BAC`

`35^(\circ)=\angle BAC`

The measure of angle BAC is 45°. Therefore the correct option is B.

Answer 2

a corner in a square is 90%

the angle BAC is half that

90/2 = 45 degrees