Answer -> (12) I'm very late haha but hopes this helps!
Answer:
Length of side of rhombus is
Step-by-step explanation:
Given Rhombus ADEF is inscribed into a triangle ABC so that they share angle A and the vertex E lies on the side BC. We have to find the length of side of rhombus.
It is also given that AB=a and AC=b
Let side of rhombus is x.
In ΔCEF and ΔCBA
∠CEF=∠CBA (∵Corresponding angles)
∠CFE=∠CAB (∵Corresponding angles)
By AA similarity rule, ΔCEF~ΔCBA
∴ their sides are in proportion

⇒ 
⇒ 
⇒ 
⇒ 
Hence, length of side of rhombus is
B. 75
First you find the area of the triangle:
(base x height)/2
(3 x 5)/2
15/2
7.5
Then you multiply by the length of the prism (10):
7.5 x 10 = 75
Using the Pythagorean theorem:
a^2 + 24^2 = 26^2
a^2 + 576 = 676
a^2 = 676 - 576
a^2 = 100
a = SQRT(100)
a = 10