If b = 7, then the value of c is...

7[tex]\sqrt{2}[/tex]
The triangle shown is a 45-45-90 triangle. This name comes from the fact the 3 angle measurements are 45, 45, and 90 degrees.
If needed, you could find the missing angle using the equation: 180 - (45 + 90) = x.
Special Right Triangles
Special right triangles allow us to use formulas and shortcuts to find missing sides easily. Another type of special right triangle is the 30-60-90 triangle. While both of these are special right triangles, they have different formulas.
Formulas
All 45-45-90 triangles have 2 types of sides: the legs (a and b) and the hypotenuse (c).
In these triangles, both of the legs are congruent.
Solving for c
Since we are given b, we can just plug the b-value into the formula that solves for c.
The answer cannot be simplified further, so this is the final answer.
Answer:
Second option
Step-by-step explanation:
It is a right triangle isosceles
a = b = 7
c = hypotenuse
[tex]c =\sqrt{7^{2}+7^{2} } =\sqrt{49+49} =\sqrt{2(49)}=7\sqrt{2}[/tex]
Hope this helps