Question

guys help me to answer it​

Answer 1

Explanation:

3. 2+√3/2-√3 = 2+√3/2-√3 × 2+√3/2+√3

= (2+√3)²/(2)²-(√3)² = 4+3+4√3/4-3

= 7+4√3/1 = 7+4√3

4.i)Let ABCD be a trapezium with,

AB∥CD

AB=25m

CD=10m

BC=14m

AD=13m

Draw CE∥DA. So, ADCE is a parallelogram with,

CD=AE=10m

CE=AD=13m

BE=AB−AE=25−10=15m

In ΔBCE, the semi perimeter will be,

s= a+b+c/2

s=14+13+15/2

s=21m

Area of ΔBCE,

A=√s(s-a)(s-b)(s-c)

=√21(21-14)(21-13)(21-15)

=√21(7)(8)(6)

=√7056

=84m²

Area of ΔBCE is,

A=1/2 × base × height

84=1/2×15×CL

CL=56/5m

Are of trapezium

A=1/2×(25+10)(56/5)

A = 196m²

Hence,the area of the trapezium is 196m²

ii)4:1

Hope it helps