∵AB⊥BC
∴△ABC是直角三角形
∴AC2=AB2+BC2=12+(
3 |
4 |
5 |
4 |
∴AC=
5 |
4 |
∴S△ABC=
1 |
2 |
1 |
2 |
3 |
4 |
3 |
8 |
∵在△ACD中AC2+AD2=(
5 |
4 |
13 |
4 |
∴△ACD是直角三角形.
∴S△ACD=
1 |
2 |
1 |
2 |
5 |
4 |
15 |
8 |
∴四边形ABCD的面积为S△ABC+S△ACD=
3 |
8 |
15 |
8 |
9 |
4 |
则四边形ABCD的面积为
9 |
4 |
3 |
4 |
13 |
4 |
3 |
4 |
5 |
4 |
5 |
4 |
1 |
2 |
1 |
2 |
3 |
4 |
3 |
8 |
5 |
4 |
13 |
4 |
1 |
2 |
1 |
2 |
5 |
4 |
15 |
8 |
3 |
8 |
15 |
8 |
9 |
4 |
9 |
4 |