Help me. Ksjsjsjs:(

a rule to know: a median divides the side into equal parts.

we know:

PR = -2a + 34

SR = 2a + 26

- based on the rule, SR is half of PR. in other words, PR is two times greater than SR.

so,

2SR = PR (now simply pluggin the expressions we have)

2(2a + 26) = -2a + 34 (solve the equation like any other equation prob.)

4a + 52 = -2a + 34

6a + 52 = 34

6a = -18

a = -3

- inorder to check if this is correct, simply reverse what we did. so pluggin the value of a to see if its correct.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

chicken chicken chicken

step-by-step explanation: