Question

Can someone step by step explain the answer to me please and thank u

Answer 1

First

angle in front of c is 30°, so hypotenuse is equal to 2c

it's right triangle, so let's use Pythagorean theorem\

$(2c)^2=c^2+4^2\\4c^2=c^2+16\\3c^2=16\\\\c^2=\dfrac{16}{3} \\\\c=\dfrac{4}{\sqrt{3} } =\dfrac{4\sqrt{3} }{3 }$

Second

b - the base of the triangle, angles at the base are equal ⇒ cathets are equal

it's right triangle, so let's use Pythagorean theorem

$b^2=7^2+7^2\\b^2=49+49\\b=\sqrt{2\times49} =7\sqrt{2}$